Wayne-
I believe the tail light bodies were Clear Zinc (Silver) and not Zinc Dichromate (Gold). As far as a plating shop, where are you located? Have you Googled plating shops in your area. This topic has been discussed here before, I can give you the name of the plater I used here in Ohio but shipping to and from might be be a killer.
Also, you might want to grab as much stuff to be plated at the same time as some of these shops have minimums. You can possibly plate a bucket full of pieces/parts for the same price of the 2 tail light bodies.
Best of Luck,
Greg