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).
Comparing the weights of frame components for Bentley and Essex models.
| Identifier | ExFiles\Box 88\3\ scan0131 | |
| Date | 8th March 1935 | |
| FILES. x258 8.3.35. WEIGHTS. Bentley. Frame & crossmembers Step-irons 2 front wing stays Body brackets 194 lbs. Essex. Frame & crossmembers Step-irons 2 Wing stays Body brackets 250 lbs. Essex frame figure should have 6 lbs. taken off for battery box. | ||