You might give Wayne Novak a call. He's in WV and if they don't do revolvers might be able to give you a lead. Alex Hamilton at Ten Ring Precision in TX could do it, but you've got shipping to contend with.

Having done a bunch of barrels professionally (long ago), it isn't a basement project. If you're in real good status with the the Big Guy upstairs, the old barrel might readily screw out and the new one right in with no fuss or bother. That generally isn't the way things turn out.

There are a whole bunch of threads on this subject, it'd be educational to read a couple.