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 Watford Aero Magnetos with their types, serial numbers, and remarks on use or condition.
| Identifier | ExFiles\Box 43\4\ Scan306 | |
| Date | 23th October 1930 | |
| X. 4021 23.10.30. X.4021. X.4513W. WATFORD AERO MAGNETOS. Same as AP.12-2 type Type. No. (R.H.) No. (L.H.) Remarks. I.S.12 (old type) 83134 83135 Obsolete type. I.S.12 I.S.12 " 83136 83137 " " I.S.12 " 83120 83119 Modified magnetos in new condition. For H.{Arthur M. Hanbury - Head Complaints} engine Type Test. I.S.12 " 83132 83133 Modified magnetos in new condition. (At Farnbro) I.S.12 " 98034 98033 Used for F.{Mr Friese} engine Type Test. SP.{Mr Spinney}12-5 98087 98089 Used on R.1. engine Partly magnesium castings. " 98088 98090 Miss England II engines. " 98101 98102 Miss England II engines. EFC. | ||