Many jewelery retailers have trade shops inside them . Most of those do rhodium plating. If you can''t find a place in NJ, the Phila. Jewelers Row area certainly has people available for this service. Generally speaking, a ring to be rhodium plated must be properly cleaned first and polished nicely before being plated. Contamination of very costly rhodium bath materials results when unclean items are plated.
Hmmm...I don''t know much about Union county. Is there a Hamiltons Jewelers near you? I have heard pretty good things about them. There has to be a reputable place near you, though.
I live in Monmouth and there are a couple places I can think of that could probably do that for you, though I don''t know for sure. Let me know if you want some names.