1963 M37 engine bearing.

[OutpostM37]

I purchased this M37 about 10 days back. It sat for 6-7 years without running. The engine oil was drained at that time. I pulled the oil pan to inspect the lower end of the engine. The oil pan was relatively clean, not having much sludge. I dropped a conrod to inspect the bearing/crank interface. The bearing was stamped 010 makes me think that it was rebuilt sometime back. Odometer shows 66k on the clock. The piston skirts that I saw were very clean like they were near new. Give me your thoughts on the bearing surface.

 

[NDT]

Looks OK but looks can be deceiving. Plastigage it to make sure clearances are in spec.

 

[teletech]

Looks about normal as such things go, I can tell you I wouldn't hesitate to drive it based on that.
Yes, I'd feel better after some plasitgage. Actually, I've had issues with the crank journals going egg-shaped so since it was a running engine I'd worry less about clearances and more about putting a mic on the journals and verify they are round.
Of course, that's just one... I've seen engines that looked pretty good on five out of six and still knock so at least wiggle them all. Unless you run the motor or completely disassemble it, it's all just an educated guess.
Good luck.