I am having the bumpers re-chromed. The rear lens frames are pitted as you say, but the workshop had said they can try to polish them to appear brighter but pits will remain. Those I have seen for sale are as bad as mine! As for the front over-riders, a clown just struck the o/s rubber from the side. I cant be sure until its removed whether the rubber is screwed up, or the bolts twisted or the hole in the bumper elongated. To avoid a late inquest I had hoped that I might just replace the pair, new for old.