I had a friend bring me an old Belgium made trade gun to look at, and see if it might be in good enough shape to shoot. I took it apart and examined all the crucial parts to make sure it was safe. When I got to looking at the barrel I found that it had a spot on the underside of the barrel that looked like it had been repaired. After cleaning the repair’, I found that it likely was repaired after its proofing in Belgium. The small crack had been sweat brazed closed and had not created problem for the rest of the guns working life.
So, on your gun, I would put the lug in the generous dovetail, and braze it in place. And don’t forget to give any new owner a heads up about the repair. I’m sure we won’t have to worry about you overloading it, you’ll be thinking about that lug every time you pull the trigger.
Hungry Horse