I didn't want to jack another thread so here's an option of a front water thermostat housing that I'll be incorporating into my build (Galant 1.8 dohc head on 4g61 block)
I had the head cleaned so I just need to put the cam/gears back in for clearance positioning. And depending on the radiator outlet, you might be able to position the angle of the T-stat outlet before affixing it.
The miata was in a bad front end accident and couldn't tell where it attached to the head, just that it was broken off.
And since people are just welding pipes in there anyway..