Interesting that nothing was there. May be difficult to find just these and you may need to get the whole tail. I have a Caprice that had Chrome Trim around the Tail lights where the Impalas are painted black. the black always seems to flake off or fade. I wanted to do something different.
It was tricky to remove the metal trim from the lights but I was able to get the rings off and have them powdercoated black. Don't belive these lights are designed to have this trim removed, since the little tabs aren't very forgiving (break after a few bends) and are difficult to get to. But it is do-able and the powder coat has been holding up well.