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).
Blueprint showing a cross-section of a Phantom II Twin Choke Carburettor.
| Identifier | Morton\M19\ img169 | |
| Date | 15th May 1931 guessed | |
| P.II TWIN CHOKE CARB. No. 1. ADJ. SCREW CLUB FOOT. No. 2. ADJ. SCREW. AHD | ||