Good stories.
Years ago I learnt another warning regarding fuel leaks : a Bellanca Scout at a gliding camp had fuel stains under one wing, it needed to be investigated. Unfortunately the next week, before any investigation of the leak, one of the wings departed on climb and the pilot was killed. Investigation showed the aircraft had been upside down on the ground sometime earlier and the wooden spar cracked but not picked up during the repair. Probably the fuel tank leak was due to stress on the tank from the wing flexing.
