Tractormanmike,
Your engine doesn't look too badly pitted. It sure needs more than just a good TLC. A few missing parts (piston cover, stephenson reversing linkage, etc.) but nothing that can't be fabricated in a small home workshop. What are the bore & stroke?
I agree with Bart about the estimated working pressure: the cylinder wall seems comfortable enough to be operated at something between 100 and, say, 150 PSI. But only 4 studs means that it's safer to operate it under 100 PSI.
By the way, this is a nice find. It will be fun to get it back into working order - not to say getting it attached to a boiler and puffing quietly in a hull!
