Yeah, I see a sump! I don't see any reed valves, just a piston valve in the inlet/outlet bore. Sure does look like it's just asking to be a steam engine. Guess I'll keep my eyes open for one of those ... you, know, for something in the future ...It looks like automotive type pistons and rings, even with a built-in oil pump! The valves are some kind of reed valves.
Air Conditioning Restoration Photo 1
Here's where I found the story:
HOME-BRED STEAM POWER
Keep up the good work! I'm interested to see what this looks like finished.