As the engine seems to form the most part of the whole thing, is it any of the following:
Curtiss OX-5 or 6
Hispano-Suiza 8-series
Packard Liberty 12
Peugeot 8 - series
R.A.F. I a or 4a
Renault 12 - series
Rolls-Royce Eagle II - VIII
Sunbeam Cossack
Wolseley Viper