Ok,

I had nothing to loose so I wanted to try something .
So,,,, I put it back together with what I have. I gutted the original 160 thermostat. so now its nothing but a restrictor plate. I also bumped timing back up to 19 degrees base. Refilled it straight distilled water , added maybe a cup more of the cooling system additive. As the bottle says treats up to 12 quarts. this one was closer to 15 qts. Took it for a 25 mile test drive. So far so good. Its stayed well below half way on the gauge. Which by my earlier test , halfway is right at 190

Ambient temps during said ride were low 80s temps

Im going to drive it several times in a couple different environments before doing anything else to it

And as soon as I find a place its hidden , I will be adding a aftermkt gauge just for good measure before going any deeper.