72 dart front grill

Gorilla glue or any quality epoxy glue. Clear. Scuff the edges with some sandpaper. Clean and degrease well. Dry. Small bead of glue. I hold each side together with some masking tape until dry. Sand smooth any excess. Paint.

I would thoroughly recommend that you do everything you want to the grill first. Clean and paint etc. tab repair is last. I repaired 1 on this grill.