Thanks harry, I wish your bikes were there with them. I would not use the pedal crank bearings for a jackshaft. They may be strong enough, but they're not sealed, they have to be greased, adjusted just right and probably often. The hanger will hold up fine but is an odd inside diameter and would need to be bushed down to a common bearing. Your experience with machinists suggests you may be better off using readily available common size tubing. Odd bearings exist but are usually cost prohibitive.
I'll check on that guys bike a couple times a month to see his progress.