The big problem was a second entry that made reference to inflight structural failure, main spar cap broken, buckled airlerons, and buckled wing skins.
Too many G's pulled? Severe turbulence? I have never heard of repairs for an "inflight structural failure" on a 150, although it certainly seems possible! My question is how do you experience enough G's to severely damage only one wing, and not do any damage at all to the other? How old are the repairs? Perhaps the 1970 "fender bender" did more damage to this wing than was actually found and repaired, leaving it in a weakened condition. Sounds like the damage was limited to the outboard wing section, in any case.
Replacing a badly damaged wing with another serviceable unit is little different from a legal standpoint than replacing an alternator, engine cowl, windshield, or anything else on the aircraft. The insurance company may have opted to replace, rather than repair the wing. The important thing is that the repairs are properly performed and documented. I can't judge the mechanic without seeing his actual logbook entry's in this matter, but I would certainly have made mention of installing a "serviceable wing". I suppose a wing swap could be logged as "repaired or replaced wing structure", but doesn't adequately describe the nature of these repairs.
That said, I think you are correct in your assumption that most 35 year old aircraft have something undesireable in their history, documented or not. That is one reason why a thorough pre-buy is important, whenever possible. Damage history doesn't mean an aircraft is not airworthy. It just means you have to verify the completeness and quality of all repairs. Properly done repairs can sometimes have higher quality (and value) than the original factory assembly. 150/150's or taildragger conversions are a prime example. Many (not all) of these aircraft were damaged, with the damage replaced and repaired by the modificatons. I have one in work myself, and I will be proud to fly it!
It is perceived by most that aircraft with damage history are less desirable. I think the truth is that aircraft without damage history are more desirable (but less plentiful). One flys as well as the other and can give comparable service. It's all in ones perception of worth.
