I'm not sure what the finish on the Duo is, but I'm going to assume it's not textured or else most polishes won't work. I've used Novus 123 to restore some game gear screens before so maybe give that a try? People also use Novus for repairing scratches in laserdiscs since you can have varying levels of abrasiveness depending on which solution (1, 2, or 3) you use.