That looks like it would have been a better way to do it. I did use a tubing cutter to scribe where i wanter to cut. I had a piece of angle iron clamped to the barrel to act as a guide and thought for sure I had follwed it. But you know hacksaws. They seem to always get off track. The angle of the cut was only slight but a square and careful filing got it trueto the bore.
For working the face I drilled a 1/2" hole in the center of a 2" piece of 1 1/8" dowel then tapped a 4" piece of 1/2" dowel thru it. I chucked the jig in my drill press and trued up one of the faces with a file. Using 2" square pieces of various grit paper and emery cloth and a half inch drill.