Brian, most likely the loop was loose to begin with and the recoil caused it to break. Sending the gun out to fix a job like this (I do believe that the top and bottom ribs will have to come off) will probably cost more than the gun is worth, in my opinion. In Brophy's book, "Plans and Specifications of the L.C. Smith" it shows both the old and new loops. There is also the piece that is tapered to fit between the barrels almost like a dovetail, it is over 2 9/16" long. It also gives the size of the set screw as being a 7-32 and using a #30 drill. You can almost forget about finding that tap, so you can use either a 8 or 10-32. It was late last night and I just guessed on size, too lazy to look it up, sorry.