| Description | Date | Identifier | |
| Outlining issues with Fafnir ball bearings received, detailing why they are unsuitable compared to company specifications. | 1st Aug 1920 | Box 20 \ 7 Scan100 | |
| Procurement of Hoffmann ball bearings from America and clarifying the number of bearings in a set. | 1st Aug 1920 | Box 20 \ 7 Scan101 | |
| Cover memo requesting remarks on an attached copy of a letter from America. | 5th Nov 1920 | Box 20 \ 7 Scan102 | |
| Letter to the Managing Director discussing replies from Derby regarding steering troubles and the quality and design of various ball bearings. | 16th Oct 1920 | Box 20 \ 7 Scan103 | |
| Page 2 of a letter to Mr. Claude Johnson regarding the price of ball bearings. | 16th Oct 1920 | Box 20 \ 7 Scan104 | |
| Extract regarding the use of Hess Bright standard steel cage bearings in all four road wheels. | 1st Jun 1921 | Box 20 \ 7 Scan105 | |
| Inter-office correspondence discussing the cost of special thrust bearings and recommending alternative standard bearings. | 27th Jun 1921 | Box 20 \ 7 Scan106 | |
| Use of 'Radax' type bearings for clutches and comparing bearing standards. | 20th Jul 1921 | Box 20 \ 7 Scan107 | |
| Covering memo for an attached letter from Springfield concerning Ball Bearings. | 20th Jul 1921 | Box 20 \ 7 Scan108 | |
| Letter discussing the issues and costs of using special inch-size ball bearings versus standard millimetre bearings. | 27th Jun 1921 | Box 20 \ 7 Scan109 | |
| Letter regarding inch size bearings and enclosing leaves from an S.A.E. handbook. | 23th Nov 1921 | Box 20 \ 7 Scan110 | |
| Policy on using metric versus inch-sized ball bearings for American production. | 23th Nov 1921 | Box 20 \ 7 Scan111 | |
| Future use of metric dimensions over English standard inch dimensions in design. | 23th Nov 1921 | Box 20 \ 7 Scan112 | |
| Letter from a supplier inquiring about a mailing list for an engineering catalog and its updates. | 25th Sep 1922 | Box 20 \ 7 Scan113 | |
| The successful testing of a New Departure No. 306 rear axle bevel pinion thrust bearing. | 13th Oct 1925 | Box 20 \ 7 Scan114 | |
| Tests of a 20 HP rear axle bevel pinion thrust. | 12th Jun 1925 | Box 20 \ 7 Scan115 | |
| Comparing wear and performance data for different thrust bearing designs. | 12th Jun 1925 | Box 20 \ 7 Scan116 | |
| Proposed modifications to the rear axle centre casing, including bearing changes and experimental lightening of the differential. | 12th Oct 1927 | Box 20 \ 7 Scan117 | |
| Erecting a hypoid axle with a 1' offset and the necessary adaptations for a New Departure bearing. | 14th Jan 1928 | Box 20 \ 7 Scan118 | |
| Proposal and alternative suggestions for a new bearing and oil retaining devices on a 1-inch offset hypoid rear axle. | 28th Feb 1928 | Box 20 \ 7 Scan119 | |
| Typed memo discussing the components and oil retaining properties of a 1' offset hypoid gear. | 5th Mar 1928 | Box 20 \ 7 Scan120 | |
| Preference for a 'New Departure' type bearing over a 'Schatz' bearing, with suggestions for fitting and oil retention. | 14th Feb 1928 | Box 20 \ 7 Scan121 | |
| Continuation page of a note discussing the specifics of bearings, oil retention, and water exclusion. | 23th Nov 1928 | Box 20 \ 7 Scan122 | |
| Request to order New Departure type thrust bearings for the 20 HP pinion. | 23th Nov 1928 | Box 20 \ 7 Scan123 | |
| List of spares supplied with the chassis for American production models. | 26th May 1921 | Box 20 \ 8 Scan001 | |
| Design modifications to a two-fold leather tool wallet, including replacing straps with handles. | 2nd Feb 1920 | Box 20 \ 8 Scan002 | |
| Update to the design of a leather tool wallet to accommodate an extra pair of pliers. | 19th Feb 1920 | Box 20 \ 8 Scan003 | |
| Contents of the leather tool wallet, specifically the number of pliers. | 23th Feb 1920 | Box 20 \ 8 Scan004 | |
| Comments and proposed solutions for issues with rear shock absorbers. | 31th May 1920 | Box 20 \ 8 Scan005 | |
| Proposal for a tool wallet from Messrs Peter Haworth & Sons. | 1st Jun 1920 | Box 20 \ 8 Scan006 | |
| Designing a special combined spanner for the rear shock absorber and thermostat controls. | 8th Jun 1920 | Box 20 \ 8 Scan007 | |
| Sheradising process as a permanent anti-rust finish for tool kit spanners. | 9th Jun 1920 | Box 20 \ 8 Scan008 | |
| Optional extras like leather spring gaiters, mascots, and tool wallets, suggesting material changes due to cost. | 29th Oct 1920 | Box 20 \ 8 Scan009 | |
| Suggesting improvements and modifications needed for the standard tool kit. | 29th Oct 1920 | Box 20 \ 8 Scan010 | |
| Screw pump for lubrication and a sketch of gas pliers. | 29th Oct 1920 | Box 20 \ 8 Scan011 | |
| Dimensions and fitting of a custom tool tray for Mr. Royce's car. | 22th Nov 1920 | Box 20 \ 8 Scan012 | |
| Supply of oxidised and nickel-plated Lucas Girder Spanners, including a special order for Mr. Royce. | 6th Jan 1921 | Box 20 \ 8 Scan013 | |
| Dispatch of two Lucas Girder Spanners and instructions for billing. | 6th Jan 1921 | Box 20 \ 8 Scan014 | |
| Stating the price for Lucas Girder Spanners is 3/5d each. | 14th Jan 1921 | Box 20 \ 8 Scan015 | |
| Potential improvements and cost-saving measures for the vehicle tool kit. | 24th Jan 1921 | Box 20 \ 8 Scan016 | |
| Extract from a meeting discussing the specifications for a 40/50 HP tool kit. | 31th Mar 1921 | Box 20 \ 8 Scan017 | |
| Suggestions for the chassis tool kit and spares. | 27th Apr 1921 | Box 20 \ 8 Scan018 | |
| The tools and spares provided in a vehicle tool kit, including the potential addition of a ratchet spanner. | 10th Dec 1936 | Box 20 \ 8 Scan019 | |
| Re-tooling of a tool kit for a 40/50 chassis. | 27th Jun 1921 | Box 20 \ 8 Scan020 | |
| The tool kit for the 40/50 chassis. | 21th Jun 1921 | Box 20 \ 8 Scan021 | |
| Query regarding the difficulty of stowing the tool kit for the 40-50 chassis and a proposal to reduce its contents for touring. | 10th Jun 1921 | Box 20 \ 8 Scan022 | |
| Poor machining on a steering box nut and an incomplete tool kit for car 6.EX. | 2nd Nov 1921 | Box 20 \ 8 Scan023 | |
| Contents and potential modifications of the tool kit for the 40/50 chassis. | 14th Nov 1921 | Box 20 \ 8 Scan024 | |
| Revisions to the tool kit for the 40/50 chassis, including spanner and extractor changes. | 18th Nov 1921 | Box 20 \ 8 Scan025 | |
| Modifications to a valve grinding tool for the 50 Chassis tool kit. | 22th Nov 1921 | Box 20 \ 8 Scan026 | |
| Modifications and updates to the tool kit for the 40/50 chassis. | 23th Nov 1921 | Box 20 \ 8 Scan027 | |
| List of suggestions for improvements and additions to the vehicle tool kit, focusing on spanners and specialized tools. | 23th Nov 1921 | Box 20 \ 8 Scan028 | |
| Standardising spanner designs and requesting metal models for Mr. Royce's inspection. | 21th Oct 1922 | Box 20 \ 8 Scan029 | |
| Poor quality of Terry spanners and the decision to manufacture future spanners as stampings. | 24th Oct 1922 | Box 20 \ 8 Scan030 | |
| Requesting the order of new detachable ball bearing spanners for experimental use and comparing them to the Lucas girder. | 15th Jan 1923 | Box 20 \ 8 Scan031 | |
| Mr. Royce's preference for a dull, fettled, and sheradised finish on spanners. | 26th Jan 1923 | Box 20 \ 8 Scan032 | |
| Proposal by Mr. Royce to revise the standard set of feeler blades for 40/50 and Goshawk chassis. | 13th Apr 1923 | Box 20 \ 8 Scan033 | |
| Urging the production of a sample set of spanners for Mr. Royce. | 24th May 1923 | Box 20 \ 8 Scan034 | |
| Checklist of tools to be always kept on a 40/50 HP car, with handwritten annotations. | 24th May 1923 | Box 20 \ 8 Scan035 | |
| List of tools for a 40/50 HP car, detailing items to be left at the garage and extra tools for touring. | 8th Jun 1923 | Box 20 \ 8 Scan036 | |
| Possibility of carrying fewer tools on 40/50 and 20 HP cars to reduce weight and save space. | 8th Jun 1923 | Box 20 \ 8 Scan037 | |
| The inspection of sample spanners, detailing incorrect thicknesses and requesting corrections. | 12th Jun 1923 | Box 20 \ 8 Scan038 | |
| Correcting errors in the dimensional comparison of sample spanners, providing a new table with jaw and handle thicknesses. | 14th Jun 1923 | Box 20 \ 8 Scan039 | |
| Technical memorandum discussing manufacturing variations and machining allowances for a spanner. | 14th Jun 1923 | Box 20 \ 8 Scan040 | |
| Continued memo detailing the modification of dies to reduce machining on spanner heads. | 14th Jun 1923 | Box 20 \ 8 Scan041 | |
| Reduction of bulky tools and equipment for the 40/50 and 20 HP models. | 16th Jun 1923 | Box 20 \ 8 Scan042 | |
| Continuation page discussing punctures, and a list of tools and equipment including a hydrometer, blanking plates, and a mallet. | 16th Jun 1923 | Box 20 \ 8 Scan043 | |
| List of standard and extra touring tools to be carried on a 40/50 HP vehicle. | 16th Jun 1923 | Box 20 \ 8 Scan044 | |
| List of standard and extra tools to be carried in a 20 HP car. | 19th Jun 1923 | Box 20 \ 8 Scan045 | |
| Discrepancies in the dimensions of sample spanners compared to their drawings, with suggestions for rectifying the production dies. | 19th Jun 1923 | Box 20 \ 8 Scan046 | |
| Letter from Mr. Olley to Mr. Hives discussing the contents and rationale for the chassis tool kit, including for cars exported to India. | 23th Jun 1923 | Box 20 \ 8 Scan047 | |
| List of tools with their approximate cost and the reasons for their omission from a standard kit. | 23th Jun 1923 | Box 20 \ 8 Scan048 | |
| List of spare parts with their approximate costs and reasons for omission from a standard kit. | 3rd Jul 1923 | Box 20 \ 8 Scan049 | |
| Appropriate lubrication tools and fittings for the 40/50 Hp. chassis tool kit. | 3rd Jul 1923 | Box 20 \ 8 Scan050 | |
| Customer complaint regarding the design of the 40/50 Chassis sparking plug box spanner, prompting a redesign request. | 29th Dec 1923 | Box 20 \ 8 Scan051 | |
| Design modification to the 40/50 HP chassis sparking plug box spanner to prevent it from jamming. | 8th Jan 1924 | Box 20 \ 8 Scan052 | |
| Recommending storage solutions for tools and spares on the 46-PK model and cars in general. | 9th Sep 1924 | Box 20 \ 8 Scan053 | |
| Primitive tool box design, a complaint from Mr. Royce, and a plan to create a standard, improved version. | 10th Sep 1924 | Box 20 \ 8 Scan054 | |
| The supply and storage of open spanners in new car models. | 16th Sep 1924 | Box 20 \ 8 Scan055 | |
| Design, manufacture, and inclusion of spanners in vehicle kits. | 6th Oct 1924 | Box 20 \ 8 Scan056 | |
| The material specification and testing of Tommy Bars. | 15th Dec 1924 | Box 20 \ 8 Scan057 | |
| Parts list for spanners and tools. | 21th May 1921 | Box 20 \ 8 Scan058 | |
| Parts list for various spanners and tools with material specifications and applications. | 22th Jun 1921 | Box 20 \ 8 Scan059 | |
| Follow-up letter to The Stromberg Carburetter Co. Ltd. regarding a request for two carburetters and information on a twin choke model. | 15th Aug 1935 | Box 20 \ 9 Scan001 | |
| Letter from Zenith Carburetter Co. Ltd. confirming a telephone conversation regarding a twin down-draft Stromberg carburetter. | 20th Aug 1935 | Box 20 \ 9 Scan002 | |
| Letter to The Zenith Carburetter Co. Ltd. requesting two chokes for a Stromberg DA-42 type carburetter. | 13th Sep 1935 | Box 20 \ 9 Scan003 | |
| Official order for a Stromberg carburetter and parts from The Zenith Carburetter Co. Ltd. | 16th Sep 1935 | Box 20 \ 9 Scan004 | |
| Letter to The Zenith Carburetter Co. Ltd. requesting the supply of a carburetter and spare parts. | 16th Sep 1935 | Box 20 \ 9 Scan005 | |
| Letter to The Zenith Carburetter Company regarding Stromberg carburetter positions and bench tests for the 20/25 model. | 17th Sep 1935 | Box 20 \ 9 Scan006 | |
| Letter from Zenith Carburetter Co. regarding Stromberg and Duplex carburetters and a proposed meeting. | 20th Sep 1935 | Box 20 \ 9 Scan007 | |
| The second page of a letter from The Zenith Carburetter Co. Limited. | 21th Sep 1935 | Box 20 \ 9 Scan008 | |
| Letter to The Zenith Carburetter Co. Ltd. suggesting a mid-week visit to the Derby works. | 21th Sep 1935 | Box 20 \ 9 Scan009 | |
| Letter to The Zenith Carburetter Co. Ltd. requesting Stromberg Carburetters and associated parts. | 21th Oct 1935 | Box 20 \ 9 Scan010 | |
| Letter to Zenith Carburetter Co. Ltd. arranging bench tests for a DA-42 carburetter. | 25th Oct 1935 | Box 20 \ 9 Scan011 | |
| Letter from Zenith Carburetter Co. Ltd. acknowledging an order for two DA.42 carburettors. | 22th Oct 1935 | Box 20 \ 9 Scan012 | |
| Letter from Zenith Carburetter Co. Ltd. arranging a meeting to discuss the manufacture of carburetters for a 12 cylinder engine. | 28th Oct 1935 | Box 20 \ 9 Scan013 | |
| Letter to Zenith Carburetter Co. Ltd. arranging a meeting in Derby with Mr. Turner. | 29th Oct 1935 | Box 20 \ 9 Scan014 | |
| Table of choke sizes and depression measurements for a Size 3 carburetter. | 29th Oct 1935 | Box 20 \ 9 Scan015 | |
| Requesting modifications to a duplex Stromberg carburetter for a Phantom III unit. | 5th Nov 1935 | Box 20 \ 9 Scan016 | |
| Payment for three outstanding invoices from Zenith Carburetter Co. Ltd. | 7th Nov 1935 | Box 20 \ 9 Scan017 | |
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