[Rasper]

It looks like your polisher is built to be driven by a flat belt. There doesn't appear to be clearance there for V-belt pulleys; if that's the case, and you were to use V-belts you would have to mount the pulleys on one of the shaft ends, or use mighty small pulleys.

I used flat belts to drive the big bandsaws and planers at my shipyard years ago. I like them.

If time is important to you, then you would be better off buying one of Caswell's mandrels. But if you're like me . . . there's not much I'd rather do than mess with some old machinery . . . then it's worth it.