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).
Postscript authorising HPS to produce six additional gearboxes.
| Identifier | ExFiles\Box 161a\3\ scan0107 | |
| Date | 17th April 1939 | |
| -2- BY.9/N.17.4.39. P.S. It was agreed to instruct HPS.{Horace Percy Smith - Experimental Factory Mgr} to produce a further six gearboxes to the present instructions. BY.{R.W. Bailey - Chief Engineer} | ||