An interesting engine, made by Bradley Engineering of Coventry, England, during the 1960s. The hot cap is in stainless steel, apparently intended to be heated by gas burner. The displacer cylinder has provision for water-cooling, the displacer piston is driven by a Scotch crank arrangement. The output shaft is driven from the crankshaft by a bevel gear. Bearings are provided by bronze Oilite bushes throughout, including the displacer rod.
The model was available as a self-assembly kit and could be used in conjunction with Meccano. I don't know how many were ever built but they are rarely seen these days - I only ever seen one other.
Base 12 x 5 inches