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 for a 20/25 Front Expansion Box with cross-sectional dimensions.
| Identifier | ExFiles\Box 104\2\ scan0165 | |
| Date | 15th January 1936 guessed | |
| 20/25 FRONT EXPANSION BOX, 13 1/2", 2", CROSS SECTIONAL DIMENSIONS, AS IN STANDARD BENTLEY, G.H.WAYMAN | ||