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).
Cost comparison for different types of Phantom III rear springs.
| Identifier | ExFiles\Box 95\2\ scan0106 | |
| Date | 13th August 1936 guessed | |
| PHANTOM III REAR SPRINGS. Standard - £ 7. 18. 3d. F.88751. Solid large eye. - £ 8. 16. 6d. F.88836 Rolled large eye - £ 7 15. 0d. Increase over standard for Solid large eye - 18. 3d. Reduction by using rolled eye - £1. 1. 6d. | ||