I’ve wondered if a low temperature solder paste would work to hold a thin shim in place. If so, the shim would be good for the rest of my lifetime or longer. I’ve had little luck with various types of super glue. The problem I’ve found with hiring a “professional” welding and refitting is invariably the surface contact is only about 10% to 30% on the hook. To check I take a Marks A Lot and blacken the repaired hook and reassemble and flex the action a number of times and then check the contact. Pathetic.
I repaired my Flues in this fashion when I still had a lathe. Made a pin the same size as the hinge pin to hold the .003 shim while soldering. Soldered the shim and trimmed the edges with an exacto knife. You had to really look to tell it had been repaired and it never failed. I was very happy with the results.