I do know of a Civilian BAE 125 that had similar, An inspector had lost his torch and blamed everyone under the sun for stealing it, anyway we used to have to annually NDT the wings for Corrosion and when the Xrays were developed lo and behold his torch, exactly where he had left it!
There was the chair in a Herc fuel tank one... is that true? found when they opened them up the next year.