Shaft109. IIRC it was Nicky Knillans,Canadian, and when asked how the hell he had managed to fly so many successful missions in it he replied something like "I don't know, only God does".
The fact that it needed one specially long and one specially short set of control cables ought to have been a dead giveaway. I think it had done a large number of sorties and had been that way since leaving the factory. It was only discovered after Gibson (or Cheshire?) flew a circuit and refused to let it fly again.
Didn't Piper lose a Chieftan on test flight for reversed ailerons and then find the next 4 airframes rigged the same on the production line?