There's several good smiths that can do it. Some will have a longer turn around time due to work load. Setting a barrel back is a common practice so it's not something a top tier smith has to do.
I've had Gary Reeder to do a couple for me and have no complaints. His turn around time was hasty and if I remember correctly, the cost was somewhere around $70 plus shipping; but don't quote me on that.
Other options is: Magnaport International; Hamilton Bowen, David Clements, Jack Huntington, Alan Harton, Ben Forkin, Andy Horvath and John Gallagher just to name a few off the top of my head.
It takes 43 muscles to frown and 17 to smile, but only 3 for proper trigger squeeze.