I can tell you from experience that carefully wrapping a bushing of Al tape onto the motor shaft works quite well.. that's exactly how I have centered quite a few 1/2A & other props. Most common use is shimming up the shaft to the next largest APC prop bushing. You'll want to burnish down the leading edge, i.e. the front edge, to make a tiny bit of a lead in angle/radius, so the edge of the tape does not catch and bunch up on a close fitting prop hole. Or chamfer the prop opening a hair, either way. It sucks when you have a good bushing made but screw it up swapping props. They get oily and try to slide off too.
Any time you can find an appropriate brass/alum/plastic tube to make a bushing, that is a more permanent fix.
I gotta check out those spinners..