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 between the standard Lucas system and the proposed R.R. double wiring system.
| Identifier | ExFiles\Box 50\1\ Scan047 | |
| Date | 22th April 1921 | |
| X. 4289 22.4.21. X.4289. COST COMPARISON OF (1) PRESENT STANDARD LUCAS SYSTEM (2) PROPOSED R.R. DOUBLE WIRING SYSTEM. X. 4172. Lucas. Switchbox (without cutout.) £2.5.0. Ammeter. £1.15.0 Lucas cutout 12.6 Junction box. £1.9.0 Steering column switch. £3.0 9 £9.12. 3 R.R. Switchbox (without ammeter) £3.11.0 Ammeter. £1.15.0 Bleriot Smith or (same C.A.V. approx) cutout. £1.13.0 Distribution board. £3.10.0 R.R. combined ignition switch. £5. 8. 6 £15.17.6 | ||