I am definitely not an expert on cylinder walls, but what I remember doing in the past was checking piston -cylinder clearance, exhaust side. Don't remember exactly for sure how much is acceptable but most used cylinders I have checked recently have around .002, occasionally close to 3, think some of the larger saws in the past were .004 to .005. Not sure what the formula for clearance is but i read something about it on this site years back.
Not sure if I would on a good 064 take a risk if I thought the plating was border line. Cheaper saw I'd go for it. If you heard the saw run before you took it apart might help determine your decision. Was it noisy, may be you could hear much piston slap? I don't "Think " it looks too bad if clearance isn't too much.