Can't help with the thread you're looking for, but how you polish the lenses is all relative to how damaged they are, and how nice you want them to be/look. After all, they're just pieces of plastic, so the typical Novus plastic polish, or headlight rejuve kits will help
. But, along with the typical haze, many lenses have deep gouges, pits, overspray, and razor knife scoring around the edges where the masking was cut prior to each paint job. Polish isn't going to take out that kind of damage. If you've got something like nice, vintage SW gauges, and want them to actually be restored, then it requires removing the gauges from the truck, and carefully, methodically, prying the bezels off from the back side (a 1/8" regular screwdriver, with one of the tip corners radiused, works well). After the bezels are off, you now have a flat surface that you can go after with an orbital sander. You may want to go as rough as 150 grit to get all the damage out quickly, working your way up through grits until you get to 5000 or finer, then use the aforementioned polish to bring them back to a mirror finish. While the bezels are off, you can strip them bare, and give them the first paint job they've had in decades that doesn't have chips, dirt, hair, etc. in the finish... or, if you're not a tedious, perfectionist, S.O.B. like me, and your soul doesn't thrive on making vintage stuff work and look like brand new, just buy some new ones
