My wife’s headlights on her car went foggy and needed to be cleaned. So I bought a headlight restoration system. I had some left over and contemplated if it would work for a turntable cover. It turned out to work really great. The key to the whole process is taking your time and sanding in order.
This is a photo of the cover before sanding.
The process can get really messy. It is best to do everything in a bathtub.
The brand that you use does not matter. I have used different kinds. Usually I pickup what ever is on sale.
When sanding you must make sure you are wet sanding.
After sanding you want to dry the cover off and make sure it has a haze and no signs of scuffs or scratches. If you see some start over.
Now polish with the included compound.
Do not use water when polishing.
This cover took twenty minutes.