marcinek:
I passed on the one with the advert on the blade and purchased one that is just scratched with some heavy scratches.
So on that one ...
I'm going to try wet/dry paper progressing in grits, starting maybe at 180, not sure yet, and them up to at least 400 and maybe more as I watch the scratch pattern getting more fine, until I'm happy with it.
I forgot that I did try the Dremel wire brush on a rusty Case Sodbuster blade and it was very very slow to remove rust.
On that one I switched to sand paper but not wet/dry. It came out ok/acceptable, but I'll be revisiting that one eventually to see if I can clean it up a bit more.