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).
Rough sketch comparing a Sheldon spring without shackles to Mack bus shackles.
| Identifier | ExFiles\Box 4\6\ 06-page11 | |
| Date | 9th June 1922 guessed | |
| Sheldon spring without shackles Mack bus shackles Rough scheme Grey June 7. | ||