Many plating shops are not set up to handle the polishing and repair work needed for antique restoration plating. Some shops only do the antiques as a side job. Their main business being plating of new mass produced parts, which are not near as labor intensive, so that type work is more profitable for them.
I used to get beautiful nickel plating done by a shop in Elmira, NY that specialized in plating new electronic components. But, they could only do nickel and only with new rolls of copper tubing I'd send them for my work when restoring engine oil and fuel lines.
And some shops that did antique work have dropped it because of lack of skilled labor. I know of a Syracuse shop that only does the plating - mostly for other plating and metal finishing shops. They stopped doing the polishing, when their last polisher quit about ten years ago. Because they have large plating tanks, they get the big pieces such as bumpers and radiator shells that are too big for other plating shops as far away as Hartford Conn. and Long Island. Sending those parts to Syracuse to be plated, then trucked back to wherever to be polished in between the layers of copper, then the nickel, then the chrome, really jacks up the cost.
What's made it tougher is that in the last 35+ years about 75% of the plating shops have gone out of business rather than sink tens and hundreds of thousands of dollars into equipment to be EPA compliant. Two other plating shops closed within the last ten years in the Syracuse area alone.
So, of the few plating shops left, they tend to be swamped with work - whether it's new, or old parts.
Paul