Hand Tools Archive
John in NM
Bushings are common for bench grinder wheels, you may be able to use one of them for this. Usually they are plastic, so you could easily cut it shorter with a hack saw. Suppliers like McMaster Carr and MSC should have those, or if you have an industrial tool supplier locally they will have them. I've only ever gotten them free with wheels, so I actually don't know much about buying them.
Another option is a bronze bushing from the hardware store. Don't know if you'll find the right size available though.
A word of caution, wire wheels can be vicious on a grinder. They grab parts out of your hand and throw them across the room. They shed wires that are like little arrows to stick in your fingers. Don't wear gloves because if you get too close you won't feel it right away and pull back before wrapping a finger into the thing. Eye protection of course - I sometimes skimp on that with abrasive wheels, but never with a wire wheel.