The Stovebolt Site Forums The Shop Area Paint and Body Shop Doors Captive Nut for Access Panel

Easy fix with the correct length Tinnerman. May have to flatten the turn up lip at radius a little to allow Tinnerman to lay flat. You also may have to trim some at the radius to get Tinnerman nut to reach to hole. Tinnerman is the brand name of an old "clip on nut" company. Then all those type became Tinnermans, like Helicoil is really helical coil insert. Hardware stores, like Ace, have a selection of Tinnermans. They come in machine screw sizes and sheet metal screw sizes. Always nice not to have to weld for non structural fastener especially if you don't have a welder.
BTW: Make sure you gently chase the good nuts while oiling threads. Just do a thread at a time, back and forth until tap gets thru. Get all the rust off that way and have fresh threads that won't tear nut loose.
Wire wheel and chase screws also.