The dial on that one actually looks pretty good. I have polished a few that were so cloudy the numbers could not be read. I used to use mirror glaze. Now I use some stuff that we use to polish airplanes at work. It does not work better than mirror glaze it just lasts a lot longer. I can't remember the name on the bottle. I have never seen these products do any damage but sometimes the results are excellent other times just ok.This is one of my Dad's Federal indicators that was passed down to me, very accurate. The crystal is some kind of clear acetate, I thought about trying to polish the yellow out but don't want to take the risk of screwing it up.