Just for some reference.
Typically platers like to use AS LITTLE plating material as possible. Why? It cost them money in both longer plating times and material. For instance, you will find that a typical gold plated electronic device (i.e. RCA plugs) will have 10 to 30 microinches of gold. If they went to 60minches, it would cost twice as much.
When you talk about chrome plating, you should have nickel under it. I would take and educated guess and say that you will have under 300 microinches (.0003inches) of plating.
Now, I can 100% promise you that you parts don't have an .0003 inch tolerance and wouldn't be surprised if the tolerances on most parts are more than 10 times that. I would guess that tolerance are held somewhere between .003 and .005 inches.
If you have tighter tolerances than that, it costs a WHOLE LOTTA money in the manufacturing process. You take a part and tell them you want .002 tolerances, and it will easily cost double of .005 .005 is a "typical" tolerance for "precision" machined parts.
That said, I have had part made that require .0002 tolerances. You just pay a WHOLE LOTTA money.
I don't think that refinishing will affect yuou much unless you decide to ad 7 mils of paint (.007 inches). The key here is "mils" are thousandths.
-Dana