Two that I can think of are the Tachman,
Tachometer Repair Restoration for Antique Classic Cars Auto, and Mr. G's,
www.mrgusa. I've had Tachman do work on a couple of instruments, sweet work. I have also seen a Mr. G's set of panels that were redone, they were quite nice.
The big issue of late seems not to be the rechroming, but getting the details painted (there is an argent painted ring, as well as the flat black.) If you're talking to different vvendors, make sure what all is being done, before you compare the prices.
Carl