I just recently noticed coolant leak around the thermostat housing, originally i thought that it was leaking around gasket/bolt area.. but ends up that it was leaking thru the actual thermostat housing..

on the outside surface it looks like some small stress cracks, but from the inside of the housing there isn't any noticable cracks..

anyways i patched up the cracked area with jb qwik and it seems to be holding up...

Has anyone else had to deal with this before?

No, I've never seen the housing leak, but coincidentally I just replaced the thermostat on my '93 SSEi yesterday, and I was surprised to find that he seal was brittle and deformed badly, there were chemical deposits around the seal mating surface, and there were pits etched into both the upper housing and the lower mating surface. I've never seen anything like that before.

Jb should hold it but uhmm you might be in some trouble if it gets any worse make sure your engine runs good or those cracks will get bigger

This is a common problem due to overtightening the bolts on the housing! Best advice is to replace the housing, gasket & use PST Sealer on the bolt threads. Torque the bolts to the proper torque, not just tighten them to whatever you see fit and you'll be fine.