This engine is the prototype of a batch of 10 made by Steven Owen. Under the base it says "P1/10" but it was not one of the 10 (information from the maker).
It's a nice small vertical engine (but not small enough to be placed in my "miniature" collection). It is an attractive design and well made.
The boiler is thick 18g copper, 1 5/8" diameter x 3 1/2" tall, with a central flue. It has a safety valve and a water level plug. It is fired by a circular vapourising meths burner.
Steam is fed directly to the rear of the engine port face, there being no regulator, lubricator or superheater. The engine is a single cylinder, single acting oscillating cylinder type, 5/16" bore x 5/8" stroke. The crankshaft is fitted with a 2" cast pewter flywheel but no pulley.
The engine appeared to be in an unused condition when acquired.