I have a few front bumper rubber tops with broken studs. What kind of repairs have been done to recover these?
I have tried a few methods and now am considering a rivet nut sunk in the rubber and using a 6mm or 8mm thread. Most aren't really a good permanent repair.
Your method of repair?

I've used drill screws on two tops that were otherwise nice. But if there is any blistering from rust damage to the inside reinforcement I would just toss them and get new ones. The ones Mark from 914 Rubber sells have stainless reinforcement. It will never turn into a bumpy mess like the originals.