I've been tweaking and tuning my RB-250 since I got it earlier this year. It's a 2003 model. When I got it, it had a standard Grover bridge, worth about $6 or so. Since the Gibson website says the RB-250 comes new with a Gibson bridge, I bought a replacement Gibson bridge from JDMC and installed it today. My goal has been to bring the banjo as close to like-new condition before I do any customizing. Anyway, I noticed a small increase in volume and clarity with the Gibson bridge. It has a thicker center leg, which may explain the improved volume. The grain also looked a bit more dense on the Gibson bridge.
I expect Gibson probably just re-branded somebody else's bridge. Does anyone know who makes the Gibson replacement bridges? Before I spend 30 bucks or more on another brand of custom bridge, it would be nice to know what I already have. It also sounds like anything is somewhat an improvement over the $6 Grovers.