Don
The slophole was done by some hack on the PA/NY border
The cast chop rechamber was done by Bruce at Flint-&-Frizzen in Clarkston. He had to remove the inch, just to clean up the throat area.
Bruce has been my "go-to" smith for 30+ years. Since I moved "up north" Al is my backup gunny, in case of emergencies.
Both of them apprenticed under Bob Snapp, so you know that both of them know what their doing (and they respect each others work)