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).
Specification sheet listing design numbers and their status or remarks.
| Identifier | ExFiles\Box 174\3\ img247 | |
| Date | 7th February 1940 guessed | |
| SPECIFICATION No PL428 ISSUE No 1 SHEET No 7 DESIGN No DETAILS L.O.P. REMARKS. DESIGN REQD PL370 PL378 DESIGN IN HAND EV{Ivan Evernden - coachwork}/OIB PL426 PL420 DESIGN IN HAND EV{Ivan Evernden - coachwork}/OIB PL378 PL378 DESIGN IN HAND DESIGN REQD PL427 DESIGN REQD TO, | ||