Somewhere in my "library" of mostly irrelevant stuff ( I think it's in one of the GUY Letard publications), I have an article on a small lathe built in a Japanese POW camp by US servicemen from mostly junk stolen from the Jap work shops at the camp. The thing will fit in a hat box and was used to build prothessis for injured camp inhabitants. It could even thread turn-buckles for joints.
It was patriated at time of Jap surrender and i think it is in the Smithsonian now.
Just googled the thing and apparently it is a British endeavor, not US.