I used the wire wheel on a grinder to take off the crap inside my gen5, then finished with 1000 grit sand paper and a soft pad dremel wheel to shine. the marker airs up and keeps pressure fine. are there some of you with horror stories of way to much taken off?

Snap some photos.

The Brillo pads should not score the metal badly at all. If there was some sort of foreign material in the marker and you began to sand-polish it without first giving the receivers a bath you might risk scratching them... so wash them out first... sand the overspray off with 300grit wet dry... move up to finer paper... finish with 000 or 001 steal wool. Sand in the direction of the "action" (in line with the moving parts) so the micro scratches caused by sanding are in the same direction as the movement of the bolts. I did not use heavy paper on the actual "tube". I added marker oil when I got to the steal wool so as to aid the "glide" while "sanding" with the wool. Just take your time.

I like power tools... like ox71 I would have used my bench wheel but did it by hand. If you use power tools go slow. If you are unsure how much material your tools will take off don't use them. Do it by hand. Slow and steady beats fast from time to time (also a good mantra to think when reloading... slow and steady).