So, I bought my 91 TA with badly delaminated tail lights. Not only that, but I think at some point in time the PO replaced the "PONTIAC" decal in the center, and either it was not correctly installed, (it's slightly crooked,) and the shadow remained from the original one. Drove me bat **** crazy.
Last year I bought a center section from a late 80s early 90s from Brett in the hopes I'd find the other 2 pieces. I polished it up, and had it ready to go, sitting on the shelf.
Fast forward, and I found an almost perfect set in the DFW Metroplex for $150. Had a friend pick them up, and he's had them in his garage till about 2 weeks ago. (They just had some superficial scratches.)
Yesterday, I got them out and wet sanded them; 320, 400, 600, 800, 1000, 1500, 2000, 3000, then polished them first with white rubbing compound, then the "progressive "Griots" polishes.
I like them so much better than the 91 lights with the Amber turn signal, and no modifications were needed for the bulbs or sockets!

 

Nice!...

 

They look really good