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).
PL.461 project for Gearbox 6' Centres, noting it as the origin for the PL.580 project.
| Identifier | ExFiles\Box 136\2\ scan0321 | |
| Date | 14th March 1941 | |
| To Rm.{William Robotham - Chief Engineer} c. to Rm{William Robotham - Chief Engineer}/HH. SECRET. 1153 Ev{Ivan Evernden - coachwork}/Tln.1/JH.14.3.41. PL.461 Project of Gearbox 6" Centres. This is the original project from which the gearbox to PL.580 has been derived and is issued to you for filing only. Tln Ev{Ivan Evernden - coachwork}/Tln. E | ||