I was going to use epoxy as others suggested, but I received a reply from the manufacturer around the same time as replies (I had asked them prior to posting but hadn't heard back yet). The Metcal stand is made of phenolic molding compound. It would ideally be repaired with a high temperature cyanoacrylate. Since the areas that might be exposed to high temperatures were not damaged and it was just the rear of the stand that needed repair, I chose to use standard cyanoacrylate at a much lower price. I've been using it now for several months and everything is working as expected.
Thank you, Chris