| Description | Date | Identifier | |
| Ground clearance specifications for the Spectre model, including comparisons with other vehicles. | 7th Nov 1934 | Box 4 \ 1 01-page148 | |
| Data sheet comparing underbody measurements for Spectre, Cadillac, and Phantom models. | 7th Nov 1934 | Box 4 \ 1 01-page149 | |
| Major improvements of the Spectre chassis compared to the present P.2 model. | 8th Nov 1934 | Box 4 \ 1 01-page150 | |
| List of ground clearance measurements for the 26-EX model when the axles are clamped to the buffers. | 7th Nov 1934 | Box 4 \ 1 01-page151 | |
| Ground clearance of the Spectre model compared to the Phantom and American cars. | 7th Nov 1934 | Box 4 \ 1 01-page152 | |
| Numbered list of minor design features and improvements. | 8th Nov 1934 | Box 4 \ 1 01-page153 | |
| Confirming a conversation about design and manufacturing details for the Spectre car. | 8th Nov 1934 | Box 4 \ 1 01-page154 | |
| Material recommendations for the specification of six Spectre chassis. | 12th Nov 1934 | Box 4 \ 1 01-page155 | |
| Requesting the setup of test rigs for Spectre Textolite gears and a Wraith chain drive. | 15th Nov 1934 | Box 4 \ 1 01-page156 | |
| Comparing the ground clearances of the Spectre and a Ph.II car, noting potential issues with the Spectre's fish tail. | 19th Nov 1934 | Box 4 \ 1 01-page157 | |
| List of ground clearances for the 26-EX model when both axles are clamped on to the buffers. | 15th Nov 1934 | Box 4 \ 1 01-page158 | |
| Clarifying a request to groove the intermediate bearings on the Spectre engine to improve lubrication. | 15th Nov 1934 | Box 4 \ 1 01-page159 | |
| Secret memo from 'Sg' to 'E' regarding design points for the Spectre model, specifically about tool storage. | 15th Nov 1934 | Box 4 \ 1 01-page160 | |
| Secret memo providing suggestions for the 'Spectre' model, focusing on the jacking system and driver visibility. | 14th Nov 1954 | Box 4 \ 1 01-page161 | |
| Potential chassis design improvements for tool storage, front-end appearance, and lighting. | 14th Nov 1934 | Box 4 \ 1 01-page162 | |
| Outlining a scheme to increase the ground clearance of the Spectre chassis by restricting rear axle rebound. | 16th Oct 1934 | Box 4 \ 1 01-page163 | |
| Visit to E.R.A. Cars at Bourne, detailing observations on their gearbox and brake systems. | 17th Nov 1934 | Box 4 \ 1 01-page164 | |
| Blueprint diagram of a brake layout for E.R.A. cars. | 17th Nov 1934 | Box 4 \ 1 01-page165 | |
| Blueprint showing brake layouts for the Phantom II and Spectre models. | 16th Nov 1934 | Box 4 \ 1 01-page166 | |
| Secret memo emphasizing the importance of secrecy regarding the new Spectre and Wraith models. | 16th Nov 1934 | Box 4 \ 1 01-page167 | |
| Modifications to the frontal appearance of the Spectre No.2 chassis, listing the relevant drawing numbers. | 16th Nov 1934 | Box 4 \ 1 01-page168 | |
| Request to produce two anti-roll rods of different diameters for the 'Spectre' car. | 19th Nov 1934 | Box 4 \ 1 01-page169 | |
| List of outstanding engineering tasks for the 'Spectre', 'Bentley', and '20/25 HP' models, addressed to MRC. | 20th Nov 1934 | Box 4 \ 1 01-page170 | |
| Gearbox failure on a Spectre car, with requests to fit new gears and either new steering geometry or rear springs. | 23th Nov 1934 | Box 4 \ 1 01-page171 | |
| Request to remove a flywheel ball bearing on a Spectre to test engine roughness for the Wraith chassis. | 30th Nov 1934 | Box 4 \ 1 01-page172 | |
| Improving slow running for the Spectre Induction System by modifying camshaft overlap. | 4th Dec 1934 | Box 4 \ 1 01-page173 | |
| Blueprint comparing the valve timing diagrams for Buick and Bentley engines. | 5th Dec 1934 | Box 4 \ 1 01-page174 | |
| Engine slow running improvements using camshaft No.1636 and Cadillac tappets. | 5th Dec 1934 | Box 4 \ 1 01-page175 | |
| Requesting investigation into steering shocks, high temperatures, and a blowing dynamo fuse on the 'Spectre' car. | 6th Dec 1934 | Box 4 \ 1 01-page176 | |
| Request to thread two rods for a temporary apparatus on the new Spectre chassis. | 10th Dec 1934 | Box 4 \ 1 01-page177 | |
| Request to manufacture new pin joint components from drawings for efficiency comparison against existing parts. | 10th Dec 1934 | Box 4 \ 1 01-page178 | |
| Blueprint for a loose fitting type pin joint socket. | 7th Dec 1934 | Box 4 \ 1 01-page179 | |
| Blueprint for a loose fitting type pin joint pin. | 7th Dec 1934 | Box 4 \ 1 01-page180 | |
| Blueprint for a link for a pin jointed mechanism. | 7th Dec 1934 | Box 4 \ 1 01-page181 | |
| Frontal appearance improvements for the 2nd Spectre (31-EX) chassis, including proposals for lamp placement and a detachable grille front. | 10th Dec 1934 | Box 4 \ 1 01-page182 | |
| Progress report on the 'Spectre' model, detailing issues and developments with its steering, suspension, and brakes. | 12th Dec 1934 | Box 4 \ 1 01-page183 | |
| Test results and modifications for the engine, gearbox, and exhaust system. | 12th Dec 1934 | Box 4 \ 1 01-page184 | |
| General car performance, detailing acceleration, carburation issues, and hill climb tests. | 12th Dec 1934 | Box 4 \ 1 01-page185 | |
| Secret memo regarding a breach of confidentiality concerning new models. | 13th Dec 1934 | Box 4 \ 1 01-page186 | |
| Spectre engine push rod loading, detailing a new experimental steel push rod. | 13th Dec 1934 | Box 4 \ 1 01-page187 | |
| Note correcting an arithmetical error in the calculation of collapsing loads for Spectre push rods. | 15th Dec 1934 | Box 4 \ 1 01-page188 | |
| Judging sloping radiator designs for the Spectre model using detachable shells. | 20th Dec 1934 | Box 4 \ 1 01-page189 | |
| Proposed modification to the Spectre front apron. | 22th Dec 1934 | Box 4 \ 1 01-page190 | |
| Criticisms of the Spectre pedals and proposing modifications to the pedal plate. | 22th Dec 1934 | Box 4 \ 1 01-page191 | |
| Meeting memo outlining progress and actions required for the 'Spectre' project, concerning chassis, suspension, and steering. | 1st Jan 1936 | Box 4 \ 1 01-page192 | |
| List of engineering points and resolutions concerning welding, braking, suspension, and drivetrain components. | 1st Jan 1935 | Box 4 \ 1 01-page193 | |
| Proposed design improvements regarding ground clearance, switchbox, propeller shaft, rear springing, and pistons for the Spectre and Wraith models. | 2nd Jan 1935 | Box 4 \ 1 01-page194 | |
| Meeting notes detailing the progress and next steps for the 'Spectre' project, including chassis tests and component modifications. | 1st Jan 1935 | Box 4 \ 1 01-page195 | |
| Status report on vehicle development points including welding, braking, suspension, and gearbox issues. | 1st Jan 1935 | Box 4 \ 1 01-page196 | |
| Design considerations for improved ground clearance, switchbox, propeller shaft, rear springing and pistons. | 1st Jan 1935 | Box 4 \ 1 01-page197 | |
| The accessibility of various Spectre components for maintenance. | 1st Jan 1935 | Box 4 \ 1 01-page198 | |
| Design requirements for engine suspension, fan adjustment, and clutch accessibility. | 1st Jan 1935 | Box 4 \ 1 01-page199 | |
| The re-design of universal joints for the mixture control on a new Spectre instrument board. | 2nd Jan 1935 | Box 4 \ 1 01-page200 | |
| Secret memo regarding an information leak about 'the Spectre' and instructions to mark future correspondence as secret. | 2nd Jan 1935 | Box 4 \ 1 01-page201 | |
| Secret memorandum offering congratulations and encouragement on the progress of the Spectre project. | 2nd Jan 1935 | Box 4 \ 1 01-page202 | |
| Progress of building experimental 'Spectre' chassis and bumper tests. | 1st Jan 1935 | Box 4 \ 1 01-page203 | |
| The progress of the Spectre project, specifically the fitment of an 'E' type Marles steering. | 3rd Jan 1935 | Box 4 \ 1 01-page204 | |
| Describing an apparatus to determine how quickly a wheel stops upon locking. | 4th Jan 1935 | Box 4 \ 1 01-page205 | |
| Instruction to modify ignition governors by replacing springs on future 'Spectre' units. | 7th Jan 1935 | Box 4 \ 1 01-page206 | |
| Spectre engine ignition tests to determine the minimum advance curve for maximum power. | 7th Jan 1935 | Box 4 \ 1 01-page207 | |
| Specifications and corrections for engine timing, contact breakers, and rotor positioning. | 7th Jan 1935 | Box 4 \ 1 01-page208 | |
| Modifications to the Spectre Governor Spring with dimensional specifications. | 7th Jan 1935 | Box 4 \ 1 01-page209 | |
| Graph of ignition advance curves for the Spectre engine. | 3rd Jan 1935 | Box 4 \ 1 01-page210 | |
| Service instructions for a 'Spectre' model car. | 8th Jan 1935 | Box 4 \ 1 01-page211 | |
| Short memo providing a timeline for the Spectre Prune Bump Tests. | 8th Jan 1935 | Box 4 \ 1 01-page212 | |
| Trialling a front roll rod for the Spectre model. | 16th Jan 1935 | Box 4 \ 1 01-page213 | |
| Urgent request to carry out a modified suspension arrangement for Spectre (J.11567). | 16th Jan 1935 | Box 4 \ 1 01-page214 | |
| The return of Spectre unit No. 2 for examination, detailing issues with piston knock, porous crankcase, and leaking gaskets. | 16th Jan 1935 | Box 4 \ 1 01-page215 | |
| Accessibility of various Spectre engine components for maintenance. | 18th Jan 1935 | Box 4 \ 1 01-page216 | |
| Report page detailing Fan Adjustment, Clutch, and Starter Motor for Spectre models, including a diagram. | 18th Jan 1935 | Box 4 \ 1 01-page217 | |
| Proposed modifications for the 'Spectre Car'. | 21th Jan 1935 | Box 4 \ 1 01-page218 | |
| Secret memo outlining delays and pending tests for the Spectre Design Work. | 25th Jan 1935 | Box 4 \ 1 01-page219 | |
| List of scheme modifications and parts for the Spectre project. | 22th Nov 1934 | Box 4 \ 1 01-page220 | |
| List of engineering modification schemes with their respective issue dates. | 20th Nov 1934 | Box 4 \ 1 01-page221 | |
| List of scheme modifications for components including the gearbox, clutch, suspension, and steering. | 3rd Jan 1935 | Box 4 \ 1 01-page222 | |
| List of engineering scheme modifications with their corresponding issue dates. | 30th Nov 1934 | Box 4 \ 1 01-page223 | |
| List of engineering modification schemes, with their reference numbers and issue dates. | 18th Jan 1935 | Box 4 \ 1 01-page224 | |
| Providing specifications for re-building three Spectre Units. | 25th Jan 1935 | Box 4 \ 1 01-page225 | |
| List of components and modifications for No. 1 Unit. | 26th Jan 1935 | Box 4 \ 1 01-page226 | |
| Specification list of ten components for the 'No. 2 Unit'. | 25th Jan 1935 | Box 4 \ 1 01-page227 | |
| List of components and modifications for No. 3 Unit. | 26th Jan 1935 | Box 4 \ 1 01-page228 | |
| Issues with insulated sparking plug covers on the Spectre engine, including misfiring and sparking. | 25th Jan 1935 | Box 4 \ 1 01-page229 | |
| Oil and water leaks found in a No. 3 unit after a 15-hour test run. | 25th Jan 1935 | Box 4 \ 1 01-page230 | |
| Technical report detailing issues and required modifications for an engine unit, including tappets, valves, and carburetors. | 25th Jan 1935 | Box 4 \ 1 01-page231 | |
| Unit test report for the Spectre No. 3 engine, comparing its performance against the No. 2 unit. | 28th Jan 1935 | Box 4 \ 1 01-page232 | |
| Engine testing, detailing issues and performance of tappets, springs, pistons, and water leaks from cylinder head gaskets. | 28th Jan 1935 | Box 4 \ 1 01-page233 | |
| Engine issues including low oil pressure, a seized dynamo drive bush, and an oil leak from the crankcase. | 28th Jan 1935 | Box 4 \ 1 01-page234 | |
| Power curve graph for the Spectre engine with an open exhaust, comparing different camshafts and pistons. | 28th Apr 1935 | Box 4 \ 1 01-page235 | |
| The refitting of original rear springs on a Spectre due to a new rubber rear axle mounting scheme. | 29th Jan 1935 | Box 4 \ 1 01-page236 | |
| Modifications made to the Spectre Exhaust System to reduce horsepower loss. | 29th Jan 1935 | Box 4 \ 1 01-page237 | |
| Tests and solutions for oil pressure loss in the Spectre engine. | 31th Jan 1935 | Box 4 \ 1 01-page238 | |
| Listing required parts and modifications for various car chassis, particularly the Spectre model. | 29th Jan 1935 | Box 4 \ 1 01-page239 | |
| List of continued modifications for the 20/25 model and a list of modifications for Bentley models. | 29th Jan 1935 | Box 4 \ 1 01-page240 | |
| Initial 12-hour test run and teething troubles of the Spectre Bumper Chassis. | 1st Feb 1935 | Box 4 \ 1 01-page241 | |
| Development report on the testing of Spectre test units, detailing findings from the first unit's noisy valve mechanism and performance. | 1st Feb 1935 | Box 4 \ 1 01-page242 | |
| Test report on No. 2 Unit, detailing issues with valve noise, tappet assembly, and running performance. | 8th Sep 1934 | Box 4 \ 1 01-page243 | |
| Engine component testing report covering tappets, bearings, an exhaust silencer, oil pressure, and ignition. | 21th Jan 1935 | Box 4 \ 1 01-page244 | |
| Test report on the performance and components of Unit No. 3, including power output and notes on tappets and timing gears. | 21th Jan 1935 | Box 4 \ 1 01-page245 | |
| Programme of changes for pistons and tappets on the Spectre Engine Unit. | 4th Feb 1935 | Box 4 \ 1 01-page246 | |
| Listing four required modifications and adjustments for the Spectre Car. | 4th Feb 1935 | Box 4 \ 1 01-page247 | |
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