From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Blueprint for a mechanical component with four equally spaced slots.
| Identifier | ExFiles\Box 179b\3\ img238 | |
| Date | 21th September 1932 guessed | |
| 4 SLOTS EQUALLY SPACED .150 .130 SCALE 1/1 | ||