The following photographs were taken by Richard Trevithick. He accompanied the successful British Wakefield Team to Wayne County Airport in Detroit where the 1936 American National Championships were also taking place.
This engine was first advertised in 1939 by "International Models [Products]" of New York as the "G9". The ads quoted a bore of 7/8" and stroke of 15/16". Later, the manufacturer seems to have moved to Boston, changed their name to "Belmont Miniature Motors" and the engine became known simply as the Belmont. No ad we've been able to trace ever stated the capacity, only the bore and stroke.