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 folder or cover sheet with a handwritten reference number.
| Identifier | ExFiles\Box 176\2\ img352 | |
| Date | 7th March 1921 guessed | |
| PL513 | ||