Correct me if I am wrong, but if you have to make an entry for an oil change, shouldn't a wing swap ring some bells?
This was talked about some time ago on this board but I can't remember when.
I do know that charles had the reason that no 377 would need to be filed but a logbook entry stating that the
wing was changed should be in the log books. If for no other reason than to let you know when it was done.
How long ago was the wing changed? assuming it was in the 70's thats 30 years of flying. I think the repair has proven it self.
I would not walk from this bird, but use this found info as a negotiating tool.