good luck on those, I happened to get them from the guy on Ebay for 80 bucks for the pair. Mine were so brittle there were holes through them. I did find a company that makes a gel kit featured on classic car restoration (on DIY) that he remade some tail lights. If you have one good one, they make a kit you can make a rtv silicone mold and the poor in the frosted plastic lense solution they make. Mold is said to be reusable and the ones on TV he made looked dead on original. That was my plan till I found 2 good ones. Sometime when I have extra money and nothing to spend it on I hope to make a couple spares to use down the road.
the company is
Alumilite - Products Alumilite and you can get their starter kits for 70 bucks I think. I know the lenses have been out of production for years because I called every source I could find online with no luck.
With the price of the kit I thought about making several additional pairs to make up for the cost of the mold making, but found good ones first.