Polishing head light covers (not lenses!)

If you're old like me, you remember that when composite headlights came out, folks were worried about the replacement costs.

Enterprising aftermarket companies came out with Plexiglas (?) covers to protect the lenses.

I just bought a 1990 Acura Integra LS sedan that came with these covers.

While they're not opaque, they are pitted and sandblasted.

Is there a method for polishing these out?

Remove them and throw them away. Even when they were brand new, those covers took a large bite out of headlamp performance. There's a reason they're Federally illegal.

OEM headlights are NLA. What does one do if one breaks a NLA headlight?

The 90 Integra's headlights have glass lenses, so they won't yellow. If you break one for some reason, like in a crash, you can get one from a junkyard.

There have been times over the years when I've chosen to regularly drive obsolete-model cars. You can't count on buying parts with a quicky phone call to the dealer or parts store; you keep your eyes open for New Old Stock (NOS) parts that you think you might need and when you find them, you buy them. You seek and find the specialist vendors of NOS parts and the specialist wrecking yards for whatever kind of car you're driving. You join the enthusiast clubs. That is the reality of driving a car that is a quarter-century old.