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).
Family tree diagram of battery ignition and coil part numbers.
| Identifier | ExFiles\Box 37\1\ scan 139 | |
| Date | 13th November 1922 guessed | |
| X.3199 - TREE OF BATTERY IGNITION AND COIL NUMBERS Battery ignition (general) X.3199. R.R. trembler Ignition (chassis) X.1520. R.R. non-trembler Ignition (chassis) X.3129. R.R. non-trembler Ignition (aero) X.3173. Trembler coils (general) X.243. Non-trembler coils. (general). X.918. R.R. Trembler coils. X.562. R.R. Non-trembler coils X.3445. 40/50 Z Coils (stabalite cases) X.3445. Special 40/50 Coils. X.3775. Original Gos. coils in mould-ensite cases. X.4079a. Taller type Gos. coils in mould-ensite cases, etc. X.4079b. 40/50 coils in stablalite cas-es used on Gos. X.4273. Taller coils, in Stabalite cases. 40/50 & 20 HP. X.4596. X 3199 | ||