| Description | Date | Identifier | |
| Letter from S. Smith & Sons enclosing blueprint Y.40936 for a tank unit arrangement, referencing Rolls-Royce drawing F.87026. | 28th Dec 1934 | Box 167 \ 4 img067 | |
| Drawing of a new electric petrol gauge with warning light contacts for the Spectre petrol tank. | 29th Dec 1934 | Box 167 \ 4 img068 | |
| Letter requesting advice on fitting electrical fuel level indicators and a replacement drawing for a tank attachment. | 17th Jan 1935 | Box 167 \ 4 img069 | |
| Internal order request for two electric petrol gauges for a Bentley chassis. | 29th Jan 1935 | Box 167 \ 4 img070 | |
| Letter from S. Smith & Sons to H.E. West regarding potential improvements to the Petrol Gauge. | 12th Feb 1935 | Box 167 \ 4 img071 | |
| Letter from S. Smith & Sons about temporary alterations to bakelite mouldings for warning light contacts. | 13th Feb 1935 | Box 167 \ 4 img072 | |
| Approval note for the Smiths' Electric Petrol Gauge drawing on the Spectre chassis. | 22th Feb 1935 | Box 167 \ 4 img073 | |
| Letter from S. Smith & Sons requesting permission to substitute a finer tooth gear for petrol gauges. | 25th Feb 1935 | Box 167 \ 4 img074 | |
| Letter to S.Smith & Sons, Ltd. regarding new petrol gauge gears, pending the completion of chassis tests. | 27th Feb 1935 | Box 167 \ 4 img075 | |
| Instructions for fitting new Bentley petrol gauges with reserve warning light contacts to two specific chassis. | 8th Mar 1935 | Box 167 \ 4 img076 | |
| Letter to S. Smith & Sons Ltd. requesting a meeting to discuss trouble with a new petrol gauge tank unit. | 21th Mar 1935 | Box 167 \ 4 img077 | |
| Letter from S. Smith & Sons arranging a visit to discuss a new Petrol Gauge Tank Unit with a warning light contact. | 22th Mar 1935 | Box 167 \ 4 img078 | |
| Return of three experimental Smith electric petrol gauges for modification. | 26th Mar 1935 | Box 167 \ 4 img079 | |
| Requesting the fitting of a new Spectre type petrol system for a car undergoing a 15,000-mile test. | 9th Apr 1935 | Box 167 \ 4 img080 | |
| Letter from S. Smith & Sons regarding tests and modifications to Tank Attachments with Warning Light contacts. | 26th Apr 1935 | Box 167 \ 4 img081 | |
| Internal request to order an electric petrol gauge and motor from Messrs. Smiths for a 20/25 chassis. | 25th May 1935 | Box 167 \ 4 img082 | |
| Confirming the free-of-charge repair and return of a Spectre Oil Gauge. | 3rd Jun 1935 | Box 167 \ 4 img083 | |
| Letter to S. Smith & Sons regarding leaks in a new electric petrol gauge tank unit for Bentleys. | 14th Jun 1935 | Box 167 \ 4 img084 | |
| Letter from S. Smith & Sons regarding the standardisation of a new Tank Unit for 'Bentley' and a leaking float issue. | 18th Jun 1935 | Box 167 \ 4 img085 | |
| Return of two new Smith electric petrol gauge meters with concave dials. | 16th Aug 1935 | Box 167 \ 4 img086 | |
| Letter from S. Smith & Sons regarding an increased cost quotation for 40/50 HP Electric Petrol Gauges. | 27th Aug 1935 | Box 167 \ 4 img087 | |
| Cost justification for a modified electric petrol gauge. | 9th Sep 1935 | Box 167 \ 4 img088 | |
| Letter from S. Smith & Sons regarding the failure and replacement of a Petrol Gauge meter. | 9th Sep 1935 | Box 167 \ 4 img089 | |
| Extra tool charges from Messrs. Smiths for a modified electric petrol gauge. | 10th Sep 1935 | Box 167 \ 4 img090 | |
| Cost and standardisation of a new Smith electrical petrol gauge for a Bentley chassis. | 10th Sep 1935 | Box 167 \ 4 img091 | |
| Short typed memo regarding the excessive cost of a petrol gauge unit. | 10th Sep 1935 | Box 167 \ 4 img092 | |
| New Smith Electrical Petrol Gauge for the Bentley Chassis and related supply issues. | 11th Sep 1935 | Box 167 \ 4 img093 | |
| Design modifications and seeking confirmation for a new scheme for electric petrol gauges with a warning device. | 13th Sep 1935 | Box 167 \ 4 img094 | |
| Letter to S. Smith & Sons regarding necessary modifications to electric petrol gauge drawings. | 13th Sep 1935 | Box 167 \ 4 img095 | |
| Technical review and critique of the Smith Electric Petrol Gauge. | 13th Sep 1935 | Box 167 \ 4 img096 | |
| Query sheet regarding materials for bushes and a locking scheme for pinion wires, accompanied by a diagram. | 13th Sep 1935 | Box 167 \ 4 img097 | |
| Letter to S.Smith & Sons, Ltd. regarding piece numbers for petrol tanks and tank units for the latest chassis. | 17th Sep 1935 | Box 167 \ 4 img098 | |
| Table of part numbers for petrol system components across various models. | 18th Sep 1935 | Box 167 \ 4 img099 | |
| Letter to S. Smith & Sons, Ltd. confirming a discussion about modifications to a new electric petrol gauge. | 18th Sep 1935 | Box 167 \ 4 img100 | |
| Letter from S. Smith & Sons regarding clarification of part numbers for tanks and petrol gauges. | 19th Sep 1935 | Box 167 \ 4 img101 | |
| Continuation letter from S. Smith & Sons regarding a Cast Bracket and warning light contacts. | 19th Sep 1935 | Box 167 \ 4 img102 | |
| List of petrol gauge components and part numbers for various car models. | 19th Sep 1935 | Box 167 \ 4 img103 | |
| Letter from S. Smith & Sons concerning modifications to a new tank attachment. | 19th Sep 1935 | Box 167 \ 4 img104 | |
| Replacement of two petrol filters with a single new one and the installation of a reserve warning light. | 19th Sep 1935 | Box 167 \ 4 img105 | |
| Requesting approval for modifications to electric petrol gauges received from Messrs. Smiths. | 21th Sep 1935 | Box 167 \ 4 img106 | |
| Letter to Messrs. S. Smith & Sons, Ltd. regarding an amended table of drawing numbers. | 28th Sep 1935 | Box 167 \ 4 img107 | |
| Letter from S. Smith & Sons confirming modifications to a Tank Unit for 40/50 HP Olympia Models. | 24th Sep 1935 | Box 167 \ 4 img108 | |
| Letter from S. Smith & Sons regarding modifications to a blueprint for a new type of tank attachment. | 27th Sep 1935 | Box 167 \ 4 img109 | |
| Confirming a patent application for a new single wire voltage compensated electrical petrol gauge. | 1st Oct 1935 | Box 167 \ 4 img110 | |
| Letter to S. Smith & Sons Ltd approving modifications to a proposed new tank attachment. | 2nd Oct 1935 | Box 167 \ 4 img111 | |
| Letter to Messrs. S. Smith & Sons, Ltd. regarding a new design for an Electric Petrol Gauge. | 3rd Oct 1935 | Box 167 \ 4 img112 | |
| Letter from S. Smith & Sons arranging a meeting to discuss electric petrol gauges. | 4th Oct 1935 | Box 167 \ 4 img113 | |
| Request to place an order for an A.C. electric petrol gauge with G.S. Oscroft & Co. Ltd. | 4th Nov 1935 | Box 167 \ 4 img114 | |
| Authorisation to fit the new 'Lantern toothed' gear from Messrs. Smiths to the petrol gauges on all chassis. | 30th Nov 1935 | Box 167 \ 4 img115 | |
| Capacity, gauge calibration, and potential design improvements for the Phantom III petrol tank. | 20th Dec 1935 | Box 167 \ 4 img116 | |
| List of petrol gauge tank unit codes for various chassis models, detailing part numbers and features. | 4th Jan 1936 | Box 167 \ 4 img117 | |
| Internal order request for one Smith Electric Petrol Gauge to drawing F.61067. | 20th Jan 1936 | Box 167 \ 4 img118 | |
| Standardisation of a new type Smith electric petrol gauge with an aluminium support, larger float, and warning light contacts. | 16th Aug 1935 | Box 167 \ 4 img119 | |
| Cost analysis for the standardisation of parts, comparing the costs of an old part versus a new part. | 4th Jul 1935 | Box 167 \ 4 img120 | |
| Attaching a schedule of Smiths' code numbers for the petrol gauge tank unit for various chassis. | 11th Feb 1936 | Box 167 \ 4 img121 | |
| Letter from S. Smith & Sons advising that two Bentley Tank Attachments are being sent for testing purposes. | 11th May 1936 | Box 167 \ 4 img122 | |
| Receipt and fitting of two Bentley petrol gauge tank units with special bearings. | 20th May 1936 | Box 167 \ 4 img123 | |
| Query to I.M. Waller regarding the exact location of a petrol leakage on a gauge tank unit. | 8th Jul 1936 | Box 167 \ 4 img124 | |
| Letter from S. Smith & Sons regarding an experimental single-wire petrol gauge for the 20/25 HP model. | 30th Jul 1936 | Box 167 \ 4 img125 | |
| Letter to H.M. Hobson Components Ltd. requesting a sample of a new type electric petrol gauge. | 31th Jul 1936 | Box 167 \ 4 img126 | |
| Letter from H.M. Hobson Components discussing the supply of a Hobson K-S Electric Telegage for trial. | 7th Aug 1936 | Box 167 \ 4 img127 | |
| Letter from a component supplier discussing modifications for fitting a mechanism. | 7th Aug 1936 | Box 167 \ 4 img128 | |
| Letter to H.M. Hobson Components regarding drawings for the Phantom III instrument board and petrol tank. | 11th Aug 1936 | Box 167 \ 4 img129 | |
| Letter from H.M. Hobson Components Ltd. acknowledging receipt of drawings for the Phantom III instrument board and petrol tank. | 12th Aug 1936 | Box 167 \ 4 img130 | |
| Letter regarding a sample electric petrol gauge, an enclosed sketch (No.460) for fitting, and a request for a tank for calibration. | 17th Aug 1936 | Box 167 \ 4 img131 | |
| Letter from H.M. Hobson Components regarding complications with fitting an electric petrol gauge. | 25th Aug 1936 | Box 167 \ 4 img132 | |
| Letter to Messrs. H.M. Hobson Components Ltd. regarding the mounting of a K.S. Electric Petrol Gauge. | 24th Aug 1936 | Box 167 \ 4 img133 | |
| Letter to H.M. Hobson Components Ltd. regarding the approval and modification of a tank sketch (No.460). | 26th Aug 1936 | Box 167 \ 4 img134 | |
| Letter concerning an employee's holiday absence and the continued work on new electrical gauges for an experimental car. | 28th Aug 1936 | Box 167 \ 4 img135 | |
| Letter from S. Smith & Sons regarding tank attachments supplied for testing. | 5th Sep 1936 | Box 167 \ 4 img136 | |
| Letter to S. Smith & Sons Ltd. regarding the supply and potential return of tank attachments used for testing. | 8th Sep 1936 | Box 167 \ 4 img137 | |
| Letter from S. Smith & Sons regarding a misunderstanding and placing a matter in abeyance. | 11th Sep 1936 | Box 167 \ 4 img138 | |
| Returning a faulty, experimental Smith single wire petrol gauge to the makers for rectification. | 15th Sep 1936 | Box 167 \ 4 img139 | |
| Letter regarding a faulty experimental petrol gauge being returned for rectification. | 15th Sep 1936 | Box 167 \ 4 img140 | |
| Letter from S. Smith & Sons regarding two Tank Attachments being supplied on loan for an indefinite period for testing. | 15th Sep 1936 | Box 167 \ 4 img141 | |
| Letter from S. Smith & Sons acknowledging a letter regarding a petrol gauge and tank attachment. | 17th Sep 1936 | Box 167 \ 4 img142 | |
| Invoice from S. Smith & Sons Ltd. for a tank attachment and petrol meter, requesting payment authorization. | 26th Sep 1936 | Box 167 \ 4 img143 | |
| Parts on loan to Messrs. Smiths for testing and a request to hold the invoice in abeyance. | 28th Sep 1936 | Box 167 \ 4 img144 | |
| Follow-up letter from H.M. Hobson Components to Rolls-Royce asking for an estimated delivery date for a tank baffle. | 29th Sep 1936 | Box 167 \ 4 img145 | |
| Letter from H.M. Hobson Components Ltd. following up on the supply of a sample Electric Gauge. | 26th Nov 1936 | Box 167 \ 4 img146 | |
| Letter to H.M. Hobson Components Ltd. regarding the delayed completion of a petrol tank. | 27th Nov 1936 | Box 167 \ 4 img147 | |
| Letter from S. Smith & Sons regarding the examination of a sample tank unit fitted with Carbon Graphitic Bearings. | 18th Dec 1936 | Box 167 \ 4 img148 | |
| The testing of a Bentley petrol gauge meter with bakelite-treated windings on chassis 6-B-IB. | 22th Jan 1937 | Box 167 \ 4 img149 | |
| Letter from S. Smith & Sons regarding an investigation into instrument costs, sample instruments, and petrol gauge issues. | 25th Jan 1937 | Box 167 \ 4 img150 | |
| Letter from S. Smith & Sons regarding a new tank unit without gears for testing purposes. | 25th Jan 1937 | Box 167 \ 4 img151 | |
| Letter to S. Smith & Sons regarding the price and standardization of a special petrol gauge tank unit with Carbon Graphitic Bearings. | 27th Jan 1937 | Box 167 \ 4 img152 | |
| Letter from S. Smith & Sons regarding an enquiry about Carbon Graphitic Bearings. | 28th Jan 1937 | Box 167 \ 4 img153 | |
| Letter from S. Smith & Sons regarding the fitting of a gearless single wire tank unit. | 8th Feb 1937 | Box 167 \ 4 img154 | |
| Letter from S. Smith & Sons agreeing to a modification for the Electric Petrol Gauge tank unit. | 11th Feb 1937 | Box 167 \ 4 img155 | |
| Hand-drawn sketches of mechanical components, including a gear, over a pre-printed typed letter. | 17th Feb 1937 | Box 167 \ 4 img156 | |
| Follow-up letter from S. Smith & Sons regarding a gearless single wire type tank attachment. | 17th Feb 1937 | Box 167 \ 4 img157 | |
| Letter to S.Smith & Sons Ltd. regarding the unsuitability of the proposed petrol gauge position due to road camber. | 22th Feb 1937 | Box 167 \ 4 img158 | |
| Standardisation of carbon graphitic bearings on the Smith electric petrol gauge. | 15th Mar 1937 | Box 167 \ 4 img159 | |
| The production implementation for a standardized part at no extra tool cost. | 24th Mar 1931 | Box 167 \ 4 img160 | |
| Standardisation of carbon graphite bearings on the Smith Electric petrol gauge for the Phantom III. | 15th Feb 1937 | Box 167 \ 4 img161 | |
| Standardisation of carbon bronze bearings for the Phantom III, to be introduced on the 'C' Series chassis. | 26th Aug 1938 | Box 167 \ 4 img162 | |
| Standardisation of carbon graphitic bearings on the Smith electric petrol gauge for the 25/30 HP model. | 15th Feb 1937 | Box 167 \ 4 img163 | |
| Standardisation of parts for production. | 21th Jun 1937 | Box 167 \ 4 img164 | |
| The deterioration of wire insulation for the Bentley petrol indicator due to oil saturation. | 21th Jun 1937 | Box 167 \ 4 img165 | |
| The standardisation of the Bentley petrol gauge wire. | 24th Jun 1937 | Box 167 \ 4 img166 | |
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