That's very interesting. I wonder if that would preserve the UV coating on the lenses. I've polished a number of these to bring them back from the dead, and that always requires the removal of the UV coating, so they go cloudy very quickly after being repaired.

I've tried acetone vapor polishing 3D printed ABS before. It works well. I have a frog on my desk that was 3D printed probably 7-8 years ago and it still looks like the day it was vapor polished. That doesn't get direct sunlight exposure though.