Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Sorry, but the engine you have listed is NOT a Saito V4PR, but rather some other make (possibly home-built from plans) of V4 engine. Yours is a single acting oscillator, while the Saito V4PR is a single acting fixed cylinder engine. It appears you have the correct box for a V4PR, and also the correct plans, but if you compare those plans to the engine you are showing, you will see that they are not the same!

All that being said, the engine that you are showing looks to be a very nice engine with reversing throttle valve and is no doubt a very capable engine that would be highly desirable for the proper application ... like say a nice launch for instance!

Ah, yes, the plans for the engine that you have listed here, are to be found on the internet as being designed by Julius de Waal, as seen here:

https://www.modelesavapeur.com/telechargements8/a-4-cylinder-v-shaped-oscillating-steam-engine.pdf

Hope that helps!