I think i'd try something like this: Borrow or buy a X-Y screw driven clamp (?, not sure what they're called). Then you'd need to fab up a framework of steel or wood for it. This way you could attach a cutter to it, then use the two hand knobs to go back and forth until it's ready to have more removed, then use the other know to push it in just a fraction. Don't know if you're following or not, kinda hard to explain, and my drawing really sux. Those X-Y units can be had mighty cheap through Grizzly, Enco, Jet, places like that.

roll on big mama!

I`ve always just clamped a board in front of the wheel and taken a piece of pipe and rolled it back and forth along the board to true an old wheel up.
Any of the ideas here will work but I never have trouble finding an old piece of pipe and a board.The clamp may be a bit of a hunt though given the state of my shop lately.