Think about a 1925-ish, 4-cylinder, OHV, 2-main bearing crankshaft engine, with the spark plugs laying horizontally into the head, under the inlet manifold.
Fixed starting handle, Magneto igntion, dynamo and starter by Lucas.
Cast iron block and head but Ali casting for crankcase and bell housing.
Water pump driven off the timing case and located in front of the case, not on the engine side, the same drive for the magneto is used for the water pump.
Dynamo also driven off the timing case, no belt. There was a belt-driven fan on a fairly long support shaft.
Any ideas what it is? I keep thinking early Singer but probably wrong.
-- Peter A Forbes Prepair Ltd, Rushden, UK email@example.com