Did you consider advising the customer to just torch it?Hell that's not even bad. I once had a Cherokee 180, that flew in mind you, that the owner had "gotten a really good deal on" on ebay.
I get into it and it turns out that it had been exported to South Africa when it was brand new in 1964, the logbooks weren't in English but it didn't matter because not a single AD had ever been performed on it in 50 years. The stabilator skins were the old style with the bumps facing out on one side and the new style with the bumps facing in on the other, and was cracked in several places so we removed that, and the rudder and the ailerons and flaps to have them all reskinned as they were all cracked in several places. With all that out of the way I noticed a corroded piece of aluminum lying in the tailcone, looked up and saw that it was one half of the pitch trim pulley bracket, reached up and pulled the rest of the bracket and the forward vertical stab mount off with my bare hands with almost no force at all.
Everything we touched on that airplane was junk. 8 months and 65000$ later it left the hangar, 10 hours later it came back with the engine making metal.