Well I went out on Friday and did a trial run, I chose a deep scratch surrounded by some not so deep scratches, on the side of the tank I hope will be the back (and thus not visible), great area for a test run.

I will upload picutres shortly. Long and short of it is thus:

Deep scratch is still there, though not as noticeable.

The smaller scratches around it seem to be gone, I am pretty happy so far. I can't see that there is any distortion from abrading the scratches out.

I am moving the tank from my parents ranch out to my garage here in the city where I can work at it more easily in the coming weeks. If I can't work the scratches out, I will probably turn it into a large sump.