Hard to tell in the photo. If damage is just on the surface, you can polish it away. If those apparent voids are in the body of the plastic, no polishing will fix it. On my 64 & 65, I used a plastic polishing kit I bought decades ago (J.C. Whitney?). It has two bottles, one more abrasive than the other though both are very fine and less gritty than standard "rubbing compound". But, both clusters had fairly clear lenses already so I was just perfecting them. I tried the polishing kit on the foggy plastic headlamps of our 2002 T&C, but it didn't help, so I am guessing that common headlamp polishing kits might be too abrasive for this task (or maybe they don't really work). For those headlamps I used 1000 then 2000 grit wet sandpaper which worked better though I eventually just bought new headlamp housings since fairly cheap.