That's a switch, blaming it on hubby.

Usually, it's wifey that breaks these LOL!!!!

I have had this problem, before. Here is what I did. Fortunately, only one piece is broken off, an easy fix. I adjust the retaining pin so the arm swivels freely. I use gorilla ACC gel and glue the broken piece on the pin and bracket. The pin repair will be permanent and non adjustable. Hold for 20 seconds or so. Let the glue cure overnight. Fill the cracks with regular ACC glue. Do it carefully so it doesn't run into the swivel joint. After that cures, sand with fine grit sandpaper, say 220 grit. Once it is smooth, then touch up with gloss black paint such as Pactra or Testors you can get at any good hobby shop. The repair will be strong and permanent. The repair will be practically invisible. Keep us posted on your progress. If the back bracket is broken in many pieces, then I would suggest buying a reproduction.
Harvey Kravitz