I noticed that at the link you provided, they have multiple shaft sizes. I believe the Delta grinder has 5/8" shaft. But as you point out, if the wheels that come with the grinder have inserts because they are realy cut larger, then I'll have to decide what to do. I'd be more tempted to buy the 5/8" Oneway balance system and use the wheels as they are (unless this is dangerous) or buy new wheels.
Thanks, Bill