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).
Photographic comparison of two different tyre treads, labelled MA1 and MA2.
| Identifier | ExFiles\Box 157\1\ scan0074 | |
| Date | 20th May 1943 | |
| MA1 MA2 20.5.43 | ||