I picked up a Ludwig Supra the other day, and it came with a 70's era Ludwig hard shell case. The hardware had some surface rust, and I cleaned that off with crumpled aluminum foil and polished the metal parts on the case. My issue is that the black shell material won't clean up very well.
I've tried Novus plastic polish, car plastic/vinyl cleaner, etc. and the plastic material has a hazy look to it, like a film. It wasn't too bad at first, but actually got worse after using the mentioned cleaners. Is there any way I can restore it to a nice shine?