Wow that's major. I had a mental image of just the rear arc having split. Is it split all the way up through the inverted dome shaped section that attaches to the base of the monitor too, or does the split route around that?
Sounds like even more of a case for reinforcement than I thought. My thought would be to keep an eye out for some flexible thin plexi (if such a thing exists) or vacuum form a thicker reinforcing strip to match the existing curve.
Course, you couldn't vacuum form directly to the existing base, because you'd melt and deform that too. So you'd have to take a mould (plaster cast) and vac form to that.
My first thoughts involved a strip of steel and some pop rivets, but I'm brutal like that :rambo: