With type, weight, and machine number specifications.
| Identifier | ExFiles\Box 170\3\ img088 | |
| Date | 10th June 1936 guessed | |
| Avery Type A721/293. T's weigh 180 lb. Machine No E3170. | ||
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).