I found a local smith that got this job done. It set me back quite a bit more than expected as the barrel had to be turned and the forcing cone recut to get the sight to line up. It shoots groups half the size of my original Vaquero and I am happy.
My suggestion to anyone looking at a caliber conversion is to expect to spend $250 for the cylinder, barrel and smith work. Unless the gun is exceptional to start with, it makes more sense (cents) to just trade for the gun you want.