Speed racer, you mention if there are any special wheels you can use for this. There definitely is. My first thought would be to use a scotchbright wheel. It's one of the most handy things I have in the shop, use it all the time. Just attaches to your bench grinder like any other wheel but has a lot of cutting power. Lots of varieties out there, but the one I have is dense grey color if that's helpful. I know it'll work on your application as I've done the very part your doing before. Easier than a dremel or roto zip. (Hate hate those tools) The wheel will leave a semi rough finish that will require additional sanding or buffing with less agressive wheels.
Sometimes with pot metal you just keep finding more holes but I think you'll be good. If you want to seal it with something after polishing I've had some luck with power sealer by wizard, although I can't attest to long term results.
Once you realize how handy these scotchbrite wheels are, you end up spending considerably less time using the sandblasting cabinet or DA sander.
Last edited by Paul Bell; Sat Jun 20 2015 05:58 AM.