RE: How to remove scratches on clear vacumm formed part?
I built many Formula One pylon racers. During the finishing process, everything was sanded including the canopy, which would fog it up so bad you could not see through it. After all the painting was done, a coat of clear was shot over the entire airplane, and the canopy got as clear as it was when new. Light going through the canopy only cared that the inside and outside surfaces were smooth, scratches covered up with the clear coat didn't matter.