This looks like one of the 5th Form (Year 10 in todays reckoning) projects I used to do with my students many years ago. From the angle of the photo it would appear that there are no unions or pipes fitted for the inlet and exhaust, one of the last jobs pupils had to do.
These little engines were often made from two castings, using files, the base and the standard, and covered nearly all the skills needed to teach basic engineering skills, reading drawings, marking out, casting, drilling, tapping, filing, turning,tapping, soft soldering and so on, students needed these skills before going on to engineering courses at Btec level at college.
Needless to say they are robust little engines and need steam pressure at no more than 20 pounds per square inch to run them, so the follow on piece, the boiler, was equally simple for those faster students, though not many ever got that far.
They are about 2 to 3 times the power of a Mamod engine and capable of powering a simple open launch, Victorian style of about 24 inches in length provided it was not to heavy.
Small Clyde Puffers (18 inch or so) and basic small tugs also worked well. They could turn 40mm standard 3 bladed prop for about 20 minutes on a boiler full, which was enough for a free running model at the time.
They were never designed to have reverse and because students rarely made the boiler, most were taken home and used for paperweights.
But they do work very well, are simple and cheap and deserve to power a modest model.
Hope this helps.....(Look up 'Simple Oscillating Engine designs by Edgar Westbury and I think Reeves of Birmingham did similar castings.)