Wormar engines were made by Worboys & Smart, who were the predecessors to Bowman. This example is the second version of the Trojan model. The first version was a horizontal design. I don't know why they decided to discontinue the horizontal version when they produced the vertical one. They could both have called the vertical one something else and sold them both.
It is a basic oscillating cylinder design, with a small boiler enclosed in an outer shroud for heat conservation. The boiler is approx 2 3/4" x 1 3/4" diam, enclosed in a 2 1/4" diameter outer case. It is heated by a Bowman style meths burner (or should I say that Bowman boilers were heated by a Wormar style burner?) It has a small steam dome and a safety valve.
Steam is fed directly to the port face of a single acting oscillating cylinder; 3/8" bore x 1/2" stroke. This is connected to a crank pin on the solid brass flywheel. The crankshaft runs in a long brass bearing tube, with a small pulley on the other end.
As acquired, the base, burner and safety valve were missing and the steam pipe needed resoldering at both ends. I also discovered when tested that the piston had been made (presumably by a previous owner) with too close clearance in the cylinder, so that it locked up solid at steam temperature! I was given a spare Wormar base, which is not the correct model but is near enough and is the correct size. I have had replica burner and safety valve made. I have fixed the other problems and the engine now runs nicely.