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).
Note confirming the receipt of three long distribution boards with auto switches, designated J, K & L.
| Identifier | ExFiles\Box 59\1\ Scan357 | |
| Date | 30th November 1929 | |
| X.6046 30.11.29. We have now received all three long distribution boards with auto switches which we are calling J, K & L respectively. FJA. | ||