Thin shell, have you had success with this procedure? Won't the heat required to flow solder on the shell discolor the surrounding chrome?
It shouldn't. The melting point is 360 degrees F. I fixed a p83 where the threaded ball had come off because the peened end had worked loose. The part was brass so I cleaned the brass and put it back into the strainer slide and peened it over with what was left. I then put a little flux on it and used my propane torch to build up solder on the end of the loose peen. It worked great and had no discoloring of the chrome.
Plumbing valves are chrome plated brass and I have soldered many of those and never had a problem.
With the brass clean and flux added, it shouldn't take that much to get the solder to flow and adhere to the exposed brass of the shell. Once cooled some careful file and sandpaper work and it should be as good as new.
If the shell is aluminum, that Alumaloy stuff would probably work. I have never used it, and their claims of it's strength are exaggerated, but to build up some missing metal long the bearing edge, it should work fine.