I recently picked up a 624 6" and want to build my own version of a 'mountain gun'. Our state requires a 5" barrel for hunting, and I personally think the 5" if perfect on an N frame. So, I'm looking for a smith who can shorten the barrel, re-mount the factory (or similar) sights, and round the butt.
Jim Stroh/Alpha Precision in Comer,GA has done three for me. As a matter of fact he is shortening a M/29 barrel to 5" for me as this is being written. Jim's work is of the highest quality, check out his website and give him a call. Tell him Bob Twining referred you.