This engine has a name plate attached with the inscription "W. J. B-L & Co. Northampton", which is almost certainly Bassett-Lowke. However, it may not have been made by B-L, just sold by them.
The vertical copper boiler is 115mm diam x 110mm high. It has a traditional sight glass as well as a pair of try-cocks. On the brass top plate, there are a weighted lever type safety valve, a steam pressure gauge, filler cap and steam regulator. It has a single smoke tube and a substantial brass chimney. The boiler sits on a cast iron base with room for a meths burner or coal grate. There is a fancy firebox door to allow access to the fire.
Steam is fed from the regulator to the steam chest, containing a slide valve. The cylinder is a cast brass one of traditional style, similar to Model Dockyard types. It is approx. 15mm bore x 32mm stroke. There is an oiling point on top of the cylinder. The piston rod is connected to a conrod, but without a proper crosshead. The coupling does, however, slide against a machined part of the frame which takes the lateral forces. The con-rod is coupled to a disk crank. The crankshaft is fitted with an 80mm diameter cast iron flywheel with curved spokes. The crankshaft is supported by a pair of brass bearings with oiling points. Between the bearings is an eccentric driving a valve rod.
As acquired it was cosmetically in fairly good condition but mechanically it needed much repair. The safety valve was in unserviceable condition and I have fitted a modern one for steaming. I have also fitted a modern gas burner. I'm pretty sure the flywheel is not original but it has been made to work. The bottom drain cock on the sight glass was missing and I had one made for me. The pressure gauge is not working but I have a working modern one that fits. There were also many other minor faults needing attention. I have retained the original gauge and safety valve for display purposes.
The first photo on the left shows the engine in working order, with the gas burner and other modern parts used for steaming.
The last but one photo on the left shows the boiler top plate in display mode.
The last photo on the left shows the engine as acquired, before repairs.