I would grind the metal smooth on both parts. Next find the center of the four hold on metal latch,center pinch holes,drill thru the four holes that were previously welded with 1/8 in drill first then with a 1/4 or 5/16 hole in latch piece only. Next match latch piece to previous welded location with clamp . Use mig welding machine with .024 or .030 wire with triple mix inert gas and plug weld. Practice on a piece of scrap metal at a hot setting to insure o good hot sound weld. If you don't weld then go to a different welder who will guarantee his or her work .total time to weld only should only take about 15 minutes. Ray Sent from my iPad using Classic Zcar Club