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).
Cross-reference note for information relating to 40/50 Horns.
| Identifier | ExFiles\Box 64\3\ scan0313 | |
| Date | 31th December 1930 | |
| X. 7550. 31.12.30. For further matter relating to 40/50 Horns (general) see X.6078. | ||