Gary:
Very well spoken. I paid for two pre-buy inspections that turned up problems with logs, long periods of inactivity and lapsed annual inspections, and other "obvious" stuff. As a buyer of a 30+ year aircraft there is just to much that a mechanic can't see on the surface unless the buyer wants to spend big money (and they don't). My solution on the third and last pre-buy was simply "find any and all corrosion" which didn't happen either. I found some on a portion of the spar under the tank covers that is not visable unless you pull the covers. Not part of any pre-buy I've heard of.
Bottom line is that you simple can't find all the problems.
My solution was to buy a plane with a run out engine and replace it - I know what I have now. And to restore the entire plane.
You can get some good deals on planes that need engines.
