You might find a jeweler or watchmaker that has a laser welder. They are often use to add material to a case prior to refinishing if dents or gashes are present. The machines are quite expensive so don’t expect a $20 repair bill. The larger watch restoration outfits (think Rolex specialists) should have a piece of equipment like this.

This is all assuming you were talking about those small hoops being broken.

If you need a rivet pin to fix a fliplock clasp just let me know and I’ll send you one.