Re: warranty
If a machine shop ever builds an engine for you, they had better guarantee it. It's pretty common for shops that do rebuilds to guarantee their work to some degree. I don't mean the 10 yr/ 100K miles type of warranty; what I'm referring to is that it pumps oil, lines are clear, bolts torqued, valves in spec- that sort of thing. You are correct that it would be unreasonable to expect a warranty on a 58 year old engine; that's not what I said, and that's not what you're implying. We're on the same page there, but I would ask for them to look over it...
Again, here's where some more experienced members might should tell you how to ask them & what to ask them. If the engine is sold as-is where-is... well, Tim covered that earlier last week, on the other engine.
Brad