There are numerous first class plating shops (non-automotive) that cater to industrial accounts in Mass & Ct. Too many to list for sure.
(and in most other areas of the country - and you can always ship the chassis)
They will take ur chassis and drop it into an acid bath that will remove all the "paint" on the surface. Standard operation prior to plating.
Depending on what sort of "paint" this was you might try testing with a few selected solvents yourself, in WELL VENTILATED AREAS (outside, eh?). Lacquer Thinner, Acetone, MEK, etc...
Oven cleaner (Lye) tends to soften some paints too.
I understand that the usual operation for pitted automotive parts is buffing, plating thick with copper, buffing smooth, replating a copper flash coat, checking for flatness (repeat if needed) then nickel, then chrome. There is soft chrome (used for domestic stuff) and hard chrome (used for industrial stuff - automotive etc). The soft chrome looks shinier, but doesn't stand up to the wear as well. I am told...
Anyhow any good or better quality industrial house can handle your problem without any difficulty. The bigger houses can be identified by the scope of their available processes - hard anodize, hard anodize with teflon, anodize, plating of assorted metals... go with a big house if you want to be sure of the level of expertise - but be prepared to pay a full tank charge unless the guy you talk to happens to like you or hobbyists in general!
_-_-bear