Signatures include: F.C. Clement, Charles Wright (In charge of the fitting shop at Humbers Coventry where W.O. developed his aero engines), R.S. Witchell (works manager at Bentley Motors throughout), P. Purves (Bentley Motors Company Buyer from 1919 onwards) H.S. Kevill-Davies (who worked alongside A.F.C. Hillstead sales dept). Measures 12 x 17 centimetres.