Good luck finding them new. You're talking about way obsolete equipment. Here's what to do:
Get some Meguires Plast-X plastic cleaner/ polish
Get some fine sandpaper, 2000 grit.
Get some rubbing compund
Get an electric drill with polishing ends. You can do it by hand, but electric buffer/ etc. will yield better results.
First, go at the lights with the rubbing compund.
Then, using the very fine sand paper and a rag soaked in water, LIGHTLY sand the light. Keyword: lightly. Use water very liberally.
When you're done with the wet sanding, dry the light very well.
Finally, go at it with the Meguires Plast-X.
After you're done, I recommend finding some kind of other plastic polish and go with two light coats.
As for aiming, drive up to a wall on a flat surface. Park about 10 feet away from the wall. Using a deep socket set (probably 10mm), aim the lights. Some Lincolns come with a leveler built into the lamp. Just keep the little bubble in the middle. You can do it youself, it's quite easy...
