Sure your looking for Gold cad and not zinc dichromate? Guessing this is for a 66?
Plenty of places can do the zinc (hung or barrel method) In parts of the country any cad is difficult to get done.
In most cases there is a minimum amount (cost) of at least $50 so one piece or a bucket will likely be the same price. I always collected up allot of extras - had them plated and then choose the best piece for my car and sold off the extras or put them in storage.
Another option I mentioned in another thread is to do you zinc (bright or silver - what ever its call in your area) with you zinc dichromate and then strip off the gold dye with a vinegar bath to return those parts to the base silver
