Max Collodi said:
Plexiglass is plastic. It is just the brand name for the acrylic plastic manufactured by the Rohm and Haas Company. Whether or not the scratches can be removed effectively depends a great deal on their extent. You could try Novus plastic polish. It is the most widely used polish in the sign and automotive industry for dealing with surface issues.http://www.novuspolish.com/
You're right of course about plexiglass being plastic. But originally, plexiglass was an acrylic form of clear plastic made with acrylic acid. But, yes, the terms are interchangeable.
I may just see if a replacement side panel is available if this headlight restore stuff doesn't work. I'd hate to spend too much on the repair of the case. It was only a $40 case to begin with.