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).
Technical drawing of a Wellworthy piston, showing dimensions and a proposed further modification.
| Identifier | ExFiles\Box 148\1\ scan0207 | |
| Date | 13th September 1939 guessed | |
| 1256 FURTHER MODIFICATION .502" 3 1/2" DIA 1/8" 1.125" R 3/8" WELLWORTHY PISTON W.P. 316 | ||