After walking HD a few times the plumbing section revealed a sanding radius template in the form of a stainless toilet flange. Glued up a handle on a 2x4 and screwed one on each end approx aligned. Used the belt sander to remove the wood and when it got to metal it was done! Was super easy and when the flanges came off the tool was ready. No sig damage to flanges which are ready to return to their normal crappy service.
The flanges also served as great handles for the sanding where a little pressure was needed on one side or the other to get it even.