I just looked at my 57E to see how much area we are talking about. There is no wedge and a very small triangle of soldier. In the past when having Briley chokes installed I have received the barrels back with a slight opening at the muzzle. The fix for me has been a #5 lead shot lightly tapped into the opening. As long as the rib is attached to the barrel with silver solder the lead solder at the end seems to be a filler. So far my crude fix looks good and is still there. A smith is always a better fix. I wouldn't do this myself to my S3 or 450EL but my 57E is another story.
Best,
Ron
