With thanks to the Napier Power Heritage Trust the following information has been confirmed for the Napier.

Napier Chassis 11167 is recorded as a T68 Colonial with a bevel back axle, delivered 30 September 1914. The T68 is a 16/22hp with a capacity of 3,153cc (31/2 in bore / 5 in stroke). The records suggest 959 16/22’s were made between 1914 and 1916. The 16/22 was an evolution of the 15hp, which had a 31/4 in bore for 2,716cc.

I have yet to confirm engine, gearbox or back axle numbers as a matching set.