This Stirling engine is similar to the current Bohm HB7 but it's not quite the same. I'm guessing that it's, perhaps, an earlier version. It operates on a simplified Stirling cycle, in gamma mode. I say simplified because there is no obvious heat exchanger between the hot and cold ends of the displacement cylinder. The displacement piston itself should provide some nominal heat exchange and storage so it can be classified as a Stirling engine.
The engine has a displacement cylinder and power cylinder mounted parallel to each other, with connecting rods connected to a common crankshaft. The hot end of the displacement cylinder is metallic and heated by a small, single wick meths burner. The cold end is fitted with cooling fins. The power cylinder is mounted on the other side of the metal frame, through which the connection is made between the two (again, providing nominal heat exchange/storage). The crankshaft has two flywheels, each with a crank pin for the two pistons.
The whole is mounted on a nice wooden base.
As bought, it was not working but after minor repairs, it now works well