GrayMatter,

A few years back I posted here about polishing some SS, you should be able
to Google that info up. Quickly, we used some Norton Abrasives unified
wheels, Bear Tek by name, to begin teh polishing process. They were 220
grit, so they did not do very much material removing, mostly just polishing.
After that we used stitched cotton wheels and rouge compounds to achieve the
final look. We were using hand held die grinders for all of the above, but
I am sure you can find what you would need to fit your bench grinder.

Best of luck,
Jim C Roberts