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 showing three views and dimensions for a circular instrument gauge.
| Identifier | ExFiles\Box 149\6\ scan0049 | |
| Date | 27th September 1937 guessed | |
| 2 3/32" DIA., 3/16", 2 9/32", 1 1/32", 2 3/16" DIA. | ||