Okay, I Googled "buff plastic scratch" and found an auto detailing
forum that discussed scratches on motorcycle helmet visors. Someone
there recommended "Novus plastic polish." It comes in three different
grades, and the price was right.
I figure this may or may not work on my floor, but it should be helpful
on my fiber glass tub, car instrument panel, 30-some odd pairs of
clouded and unusable safety glasses, scratched NetFlix DVDs, microwave
door, router sight window, etc. I'm starting to wonder how I made it
this far in life without it.
It'll be nice if it works on polyurethane as well.