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).
List of mileages recorded for old type differential boxes on various experimental cars.
| Identifier | ExFiles\Box 92\5\ scan0095 | |
| Date | 23th November 1936 | |
| LIST OF MILEAGES DONE ON OLD TYPE DIFFERENTIAL BOXES. 31-EX - in France - 9,000 32-EX ................. 35,500 36-EX (Total Unchanged) ... 13,000 33-EX ................. 24,000 34-EX ................. 30,000 23.11.36. | ||