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).
Price list for Peto & Radford batteries.
| Identifier | ExFiles\Box 50\1\ Scan052 | |
| Date | 8th February 1922 | |
| X 4289 8.2.22 X.3398PETO & RADFORD BATTERIES. X.4414P X.4289. The quoted quantity prices of P & R batteries are as follows :- P & R B.D.11 £5.12.6 " B.D.7 £3.10.0 " H.D.E.9 £3.18.6 EFC. | ||