| Description | Date | Identifier | |
| Proposed experimental design for brake covers to prevent mud and stone ingress. | 21th Jul 1925 | Box 32 \ 2 Scan077 | |
| Proposed simple cover design for the 40/50 HP rear brakes. | 1st Jul 1925 | Box 32 \ 2 Scan078 | |
| Semi-hydraulic brake system, noting a similar design by the Sunbeam Co. and questioning the patentability of their own design. | 17th Oct 1932 | Box 32 \ 2 Scan079 | |
| Potential substitution of Duralumin with hard rolled aluminium sheet for Brake Cover Plates to achieve a cost saving. | 16th Dec 1932 | Box 32 \ 2 Scan080 | |
| Running aluminium brake carrier plates on cars in France. | 15th Feb 1933 | Box 32 \ 2 Scan081 | |
| Test report on the extension of two Bensport front brake ropes under sustained load. | 11th May 1933 | Box 32 \ 2 Scan082 | |
| Analysis of an uncompensated braking system with mathematical formulas and test results. | 25th Sep 1933 | Box 32 \ 2 Scan083 | |
| Proposal to redesign the front brake equaliser mechanism for improved efficiency and lower cost. | 25th Sep 1933 | Box 32 \ 2 Scan084 | |
| Requesting a valve modification to resolve an issue with brake thumps. | 13th Oct 1933 | Box 32 \ 2 Scan085 | |
| Blueprint of a valve for a front brake dashpot, including specifications for an internal spring. | 13th Oct 1933 | Box 32 \ 2 Scan086 | |
| Blueprint of a Type 33 steering axle with 45 Hispano brakes. | 12th Apr 1923 | Box 32 \ 2 Scan087 | |
| Pricing and discount information for Wakefields Castrol Racing Oil. | 8th Dec 1911 | Box 32 \ 3 Scan001 | |
| Letter from C.C. Wakefield & Co requesting an appointment for their representative, Mr. Still. | 29th Jul 1912 | Box 32 \ 3 Scan002 | |
| Letter from C.C. Wakefield & Co. proposing a 10,000-mile trial of their motor oil. | 7th Aug 1912 | Box 32 \ 3 Scan003 | |
| Letter detailing proposed modifications to a crankshaft and flywheel to reduce vibration and increase power, with an attached internal handwritten note. | 22th Jul 1912 | Box 32 \ 3 Scan004 | |
| Letter to C. C. Wakefield & Co. requesting samples of touring and racing oil for testing. | 29th Aug 1912 | Box 32 \ 3 Scan005 | |
| Letter from C.C. Wakefield & Co. sending two motor oils for testing and detailing the properties of their touring oil. | 31th Aug 1912 | Box 32 \ 3 Scan006 | |
| Letter from C.C. Wakefield & Co. regarding the performance of their product in various race cars. | 31th Aug 1912 | Box 32 \ 3 Scan007 | |
| Sending two samples of Wakefield's oils, a racing and a touring oil, to Prices for analysis. | 17th Sep 1912 | Box 32 \ 3 Scan008 | |
| Letter to C.C. Wakefield & Co. confirming receipt of two types of oil for testing purposes. | 17th Sep 1912 | Box 32 \ 3 Scan009 | |
| Letter from Price's Patent Candle Company regarding the analysis of Wakefield's Racing and Touring Oil samples. | 11th Oct 1912 | Box 32 \ 3 Scan010 | |
| Laboratory report from Price's Patent Candle Company comparing the properties of various motor oils. | 10th Oct 1912 | Box 32 \ 3 Scan011 | |
| Departmental memo comparing the properties of Wakefield's Racing and Touring Oils against Price's Motorine 'B' oil. | 15th Oct 1912 | Box 32 \ 3 Scan012 | |
| Departmental memo discussing the stability and fatty acid content of Wakefield's Oils. | 15th Oct 1912 | Box 32 \ 3 Scan013 | |
| Return of Price's report on Wakefields oils. | 24th Oct 1912 | Box 32 \ 3 Scan014 | |
| Departmental memo forwarding correspondence and reports concerning the tests of Wakefields Oils. | 31th Jan 1913 | Box 32 \ 3 Scan015 | |
| Internal query regarding the suitability of Wakefield's Castrol heavy 'A' Lubricating oil for six-cylinder engines. | 12th Aug 1913 | Box 32 \ 3 Scan016 | |
| Responding to a query about Wakefield's Oil, stating it has not been tested but can be obtained for testing purposes. | 13th Aug 1913 | Box 32 \ 3 Scan017 | |
| Letter from L.C. Seligmann & Co. inquiring about the recommended use of Wakefield Castrol oil. | 4th Nov 1913 | Box 32 \ 3 Scan018 | |
| Standardisation of Castrol oil for car engines. | 22th Sep 1919 | Box 32 \ 3 Scan019 | |
| The performance of Wakefield's Castrol lubricating oil in experimental cars. | 1st Jun 1920 | Box 32 \ 3 Scan020 | |
| The performance of Castrol oil compared to other oils, particularly regarding its low setting point and carbon formation. | 8th Jun 1920 | Box 32 \ 3 Scan021 | |
| Copy of a telegram from Mr. Royce regarding the use of castor oil as a lubricant. | 15th Mar 1915 | Box 32 \ 3 Scan022 | |
| Telegram with instructions regarding a defective rod, lubricant, and continued testing. | 19th Mar 1915 | Box 32 \ 3 Scan023 | |
| 10,000-mile trial of Castrol lubricating oil, detailing engine condition and chemical analysis. | 19th Mar 1915 | Box 32 \ 3 Scan024 | |
| Article explaining the layout and function of the Westinghouse Morse cam-shaft drive and chain adjustment system. | 31th Dec 1919 | Box 32 \ 3 Scan025 | |
| Letter from C.C. Wakefield & Co. regarding the supply of Castrol 'R' oil in Paris for an experimental car. | 31th Dec 1919 | Box 32 \ 3 Scan026 | |
| Potential recommendation of Castrol oil for car engines, pending further testing. | 22th Sep 1919 | Box 32 \ 3 Scan027 | |
| The use of Castor Oil for lubricating the clutch. | 14th Nov 1919 | Box 32 \ 3 Scan028 | |
| Benefits of using a good quality lubricating oil like Castrol over pure mineral oil. | 11th Jun 1920 | Box 32 \ 3 Scan029 | |
| The recommendation of Castrol oil for car engines. | 21th Jul 1920 | Box 32 \ 3 Scan030 | |
| Potential use of Castrol oil as a standard practice for car engines, pending further testing. | 22th Sep 1919 | Box 32 \ 3 Scan031 | |
| The performance of Wakefields Castrol 'R' Oil in experimental car engines and gearboxes. | 22th Jul 1920 | Box 32 \ 3 Scan032 | |
| Note confirming the engine of chassis 1.EX was refilled with 'Castrol' and that Mr. Royce personally overhauled the chassis. | 6th Aug 1920 | Box 32 \ 3 Scan033 | |
| Various mechanical issues and observations for chassis 1EX. | 10th Aug 1920 | Box 32 \ 3 Scan034 | |
| Inquiry regarding the supplier and specification for a specific Castor Oil lubricant at the request of Mr. Royce. | 12th Aug 1920 | Box 32 \ 3 Scan035 | |
| Short memo specifying the use of Wakefields Castrol racing 'R' as the castor oil lubricant. | 1st Aug 1920 | Box 32 \ 3 Scan036 | |
| Coded cablegram from Springfield about purchasing Wakefield Castrol and a request to standardize it. | 27th Sep 1920 | Box 32 \ 3 Scan037 | |
| Distributing standardisation sheets for Wakefield Castrol 'R' Oil, a Whittle belt, and a silencer modification. | 4th Oct 1920 | Box 32 \ 3 Scan038 | |
| Standardisation of chassis parts concerning the use of Wakefield Castrol 'R' Oil to reduce engine wear. | 4th Oct 1920 | Box 32 \ 3 Scan039 | |
| Advantages of using high-quality, castor oil-based lubricating oils. | 10th Oct 1920 | Box 32 \ 3 Scan040 | |
| Benefits of using less castor oil, leading to reduced running costs and extended overhaul intervals. | 1st Oct 1920 | Box 32 \ 3 Scan041 | |
| Suitability and potential standardisation of Wakefields Castrol 'R' oil. | 13th Oct 1920 | Box 32 \ 3 Scan042 | |
| Letter to Wakefield & Co. seeking an expert opinion on the effects of mixing Castrol 'R' oil with ordinary mineral oil. | 13th Oct 1920 | Box 32 \ 3 Scan043 | |
| Letter from C.C. Wakefield & Co. regarding the suitability of mixing Castrol 'R' oil with other high-grade lubricants. | 14th Oct 1920 | Box 32 \ 3 Scan044 | |
| Letter from C.C. Wakefield & Co. regarding Castrol 'R' oil for use in cars. | 14th Oct 1920 | Box 32 \ 3 Scan045 | |
| Extract from a letter to the editor of 'MOTOR TRACTION' regarding lubricating oil supplies. | 8th Nov 1920 | Box 32 \ 3 Scan046 | |
| Page 2 of a letter by David J. Smith discussing experiments with graphite-based lubricating oils like Suspensol. | 11th Nov 1920 | Box 32 \ 3 Scan047 | |
| Letter to the editor of 'Motor Traction' regarding lubricating oil supplies and piston efficiency. | 11th Nov 1920 | Box 32 \ 3 Scan048 | |
| Letter detailing engine oil analysis and the performance of new piston and ring sets in vehicles. | 26th Oct 1920 | Box 32 \ 3 Scan049 | |
| Recommendation to use Wakefields Castrol 'R' Oil for the demonstration car. | 26th Oct 1920 | Box 32 \ 3 Scan050 | |
| Cylinder wear and potential solutions involving different lubricating oils, piston rings, and oil change schedules. | 3rd Nov 1920 | Box 32 \ 3 Scan051 | |
| Letter from C.C. Wakefield & Co. Limited discussing the comparative properties of paraffin and asphaltic base oils. | 16th Nov 1920 | Box 32 \ 3 Scan052 | |
| Letter from C. C. Wakefield & Co. regarding the history of mineral lubricating oils. | 16th Nov 1920 | Box 32 \ 3 Scan053 | |
| Comparison of engine starting tests using Prices' 'C' Oil and Castrol Oil on a 40/50 engine. | 14th Dec 1920 | Box 32 \ 3 Scan054 | |
| Motor starter tests comparing performance with Prices' 'C' oil and Castrol oil. | 11th May 1940 | Box 32 \ 3 Scan055 | |
| Internal memorandum regarding a formal reply on the subject of 'Castrol' Oil. | 2nd Feb 1921 | Box 32 \ 3 Scan056 | |
| Recommendation to address U.S.A. customer complaints of cylinder wear by using a lubricant composed of 80-90% castor oil. | 8th Jun 1921 | Box 32 \ 3 Scan057 | |
| Letter from C.C. Wakefield & Co. listing their international arrangements for 'CASTROL' oil. | 17th Nov 1921 | Box 32 \ 3 Scan058 | |
| Letter from C.C. Wakefield & Co. Ltd. regarding international agents and the availability of Castrol oil. | 17th Nov 1921 | Box 32 \ 3 Scan059 | |
| The availability of Wakefields XL Castrol Oil in foreign countries for the 40/50 HP chassis. | 18th Nov 1921 | Box 32 \ 3 Scan060 | |
| Letter from C.C. Wakefield & Co. Ltd. to Rolls-Royce detailing their agents for 'CASTROL' oil abroad. | 17th Nov 1921 | Box 32 \ 3 Scan061 | |
| Letter from C.C. Wakefield & Co. Ltd. discussing the international distribution of 'CASTROL X.L' oil. | 17th Nov 1921 | Box 32 \ 3 Scan062 | |
| Confidential memo addressing the unauthorized publication of motor oil recommendations for the 20-HP model by Wakefield's. | 6th Mar 1922 | Box 32 \ 3 Scan063 | |
| Clarifying Wakefield Company's oil recommendations for 20-HP models. | 6th Mar 1922 | Box 32 \ 3 Scan064 | |
| Apology from Wakefield's for mistakenly referring to the 20-HP model in their price list. | 16th Mar 1922 | Box 32 \ 3 Scan065 | |
| Laboratory report comparing the properties of Adcol Light Racing Oil, Adcol Heavy Racing Oil, and Wakefield's XL Oil. | 28th Nov 1923 | Box 32 \ 3 Scan066 | |
| Dissatisfaction with Prices Oil, plans to test alternatives, and the current recommendation of Duckhams Oil to customers. | 18th Dec 1923 | Box 32 \ 3 Scan067 | |
| Recommendation to use Castrol XL oil as a suitable alternative for 40/50 HP and 20 HP cars. | 3rd Jun 1924 | Box 32 \ 3 Scan068 | |
| Increase in the price of Castrol oil. | 24th Jul 1924 | Box 32 \ 3 Scan069 | |
| Laboratory report comparing an unused and a used sample of 'Castrol' Oil. | 2nd Feb 1925 | Box 32 \ 3 Scan070 | |
| Order for a 50-gallon barrel of XL Oil to be dispatched to Mr. Lidsey in France. | 2nd Feb 1925 | Box 32 \ 3 Scan071 | |
| Letter from Wakefield & Co. (Castrol) regarding dissatisfaction with information provided for 'R' and 'XL' oils. | 1st Apr 1925 | Box 32 \ 3 Scan072 | |
| Internal request to order a 50-gallon barrel of Wakefields 'XL' Motor Oil for delivery to Chateauroux, France. | 6th Apr 1925 | Box 32 \ 3 Scan073 | |
| Letter following up on a previously promised reply and an order for France. | 16th Apr 1925 | Box 32 \ 3 Scan074 | |
| Order for two 50-gallon barrels of Wakefield's 'XL' Motor Oil for delivery to Chateauroux, France. | 12th May 1925 | Box 32 \ 3 Scan075 | |
| Letter to Messrs. C.C. Wakefield Ltd. requesting the composition particulars for 'XL' lubricating oil. | 21th May 1925 | Box 32 \ 3 Scan076 | |
| Letter from C.C. Wakefield & Co. detailing the composition of Castrol 'XL' Motor Oil. | 22th May 1925 | Box 32 \ 3 Scan077 | |
| Letter regarding the dispatch of two barrels of Castrol K.L Motor Oil to Chateauroux, France, quoting correspondence from C.C. Wakefield & Co. Ltd. | 6th Jun 1925 | Box 32 \ 3 Scan078 | |
| Letter from C.C. Wakefield & Co. regarding the supply and promotion of Castrol oil for Rolls-Royce cars on the Riviera. | 29th Jun 1925 | Box 32 \ 3 Scan079 | |
| List of garages in Marseilles, South of France, that stock Castrol oil. | 29th Jun 1925 | Box 32 \ 3 Scan080 | |
| List of agents and garages located in various cities in France, page 2. | 29th Jun 1925 | Box 32 \ 3 Scan081 | |
| Typed list of agents and garages located in various French cities. | 29th Jun 1925 | Box 32 \ 3 Scan082 | |
| Page 4 of a list of garages and mechanics located in various districts of France. | 29th Jun 1925 | Box 32 \ 3 Scan083 | |
| List of contacts and addresses in the Pyrenees regions of France, page 5. | 1st Sep 1925 | Box 32 \ 3 Scan084 | |
| Request for samples of Shell Super Light Racing Oil for analysis and testing. | 1st Sep 1925 | Box 32 \ 3 Scan085 | |
| Performance of Shell super light racing oil compared to other compound and fatty oils. | 24th Oct 1925 | Box 32 \ 3 Scan086 | |
| Inquiry about the availability of Castrol 'XL' oil in various locations in France. | 5th Jan 1926 | Box 32 \ 3 Scan087 | |
| Letter from C.C. Wakefield & Co. Ltd regarding car testing in France and a request for a list of stockists. | 6th Jan 1926 | Box 32 \ 3 Scan088 | |
| Letter from C.C. Wakefield & Co. about the availability of Castrol 'XL' motor oil in the South of France. | 8th Jan 1926 | Box 32 \ 3 Scan089 | |
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