It appears grinder suggestions win out, but I already have too many grinders and I also have a few buffers.
I had one US army surplus wet belt sander also. But that thing is one too many and I have to donate it to a rebuodbware hoise store. The store listed it for $300 for many months then it's gone. Hopefully someone bought it.
Oh, wait, I got one more wet grinder that I need to get working and it looks like this:
I just measured and the shaft diameter, which I still have is 1". The bolt holes are 1/2".
View attachment 307789
You guessed it right. It came from an exercise machine. That's a cable wheel and the bottom is the shaft where maybe for either bicept or calf exercise.