This may sound crazy, but ive had deep scratches in my plastic, I used a propane torch to heat the scratch and it kinda melted, blended, with the rest of the plastic, dont get the plastic too hot though, dont keep the flame at on one spot too long or you will burn the plastic, a few quick passes with the torch and the scratches were hardy noticeable. I use that trick with lexan and plexiglass to make the edges clear and smooth after cutting