I think I’d like to see the pump work. You can always restore later. I like that drain on the cross head guide.
Hi Jack, Nice find! The pumps are made for scale live steamers and can be bought in a few different sizes. They are clever little buggers. The ratchet drive allows it to run the internal pump (which resembles an oscillating steam engine) to work at a very slow speed. Looks like the previous engineer added an in line ball check valve above the original oil cup. It is a nice and interesting and functional set up even if not of the best looking parts. You could still polish them and make it all look pretty good. You are correct in that it is definitely not original.
I would guess that the roller on the throttle governor pin was added for a little extra weight as it serves no other reasonable function unless a little spring inside went off to parts unknown. This happens if you are not careful when you remove the 3 screws holding the flange on the governor throttle body. That said.... I am not certain the spacer collar would even help with a missing spring without taking one apart which I haven't enough time for right now.