73 Dart Sport - What kind of gaskets go around the taillights?

What you're talking about sounds very much like the white foam around the studs on the rear tail panel piece of my '65 Barracuda. It was shot, so I replaced it with some other foam stuff that was sticky on one side. Thanks a lot for the help!

I'm helping my friend with his '73 Dart Sport (B5 Blue/B5 Blue) and the taillights are my responsibility to clean up and put back in.