Jakeroo, I have an early 60s Superposed Magnum with the thick plastic-y finish that looked a bit like a bear had sharpened his claws on one side when I got it. After doing a bit of research I tried cyanoacrylate glue (superglue) to fill the gouges. Smoothed it down with 800 grit paper, and then polished it with an acrylic polish (Novus plastic polish). The repair is invisible.
I'm torn about refinishing mine. It has very nice wood and I do think it could look much better, but it is also my #1 duck gun, and there are times I'm glad I have that thick tough finish.
