Epoxy, sandpaper and paint....especially if it's a rare item. I epoxied LUX wheels some ten yrs ago that were smashed and use the vacuum to this day. It's an art using epoxy though; how well you mix, how long you fiddle with setting part, how long you cure the repair and the epoxy itself. If you build up the inside joints you can't see, you can sandpaper the show side flush & paint.
Kevin