Rear hatch crack/seal/repair Q

My rear hatch is plastic or fiberglas. It now leaks. In the top right corner (facing forward looking at it from outside) there is an external crack from the glass gasket to where the first ridge is - about 3" or so. It doesn't gap open, but it flexes a bit and has cracked the paint.

I also now have a leak in that area of the door. On closer inspection, water is coming in from under the glass seal. I pealed it back and the two halves of the door construction the might usually be glued there have separated, and water is getting/flowing in the crack. Maybe from glass seal, maybe from the crack.

It looks like it's a stress point. The window also seems to want to come right out as I peel back the gasket. Is it normally that loose fitting? I'm used to next-to-impossible to get glass out.

The big question is - has anyone got any experience beefing this corner up to prevent re-cracking, and would just gluing the 2 clamshell door skins together under the gasket be OK? If I left the external crack alone, and it did have some water infiltration, it would run down the inside where there should be drainage anyway, right?

Other ideas? It isn't big structural damage yet, so a new hatch might be overkill.

Help... Anyone???

I'd like to fix this before it gets worse - it looks like it gets pulled on every time I close the rear hatch door.

I know what you mean. I've seen the same stress-caused "tearing" of the fiberglass on both sides of the rear hatch on several old XJs. I suppose you could try to cut a strip of sheet metal for both sides, rivet it on then bondo over it smooth and paint it. I don't know if it would hold up much better than the fiberglass already there, but if the hatch has basically separated into 2 pieces then you have little to lose.