Thank you--took car back to the shop for the 6th time and gave them your questions.
It appears there is a small leak in the radiator core, no-one could see because it was leaking on the firewall, no signs of leaking anywhere else.
First visit started with--had been filled to high last check (which they did)
Then came all the flushes, hose replacements, hose change arounds (they said hoses had been backwards) , pressure tests, core checks, thermostat replacement and all the while being told there was nothing wrong with the core, there are no leaks.
They refilled everything and was told will get a little heat until it gets to the point back where it was--still only warm in one vent. An added $1500 repair has to be thought out after all that's already been done--is this really what's wrong, or another step to find what's wrong?
Other than freezing, is it a health issue driving the car with a leak?
Thank you for your time and information, the car is not fixed, but you did provide me with data giving me more power to push a little harder to get someone to check deeper. Would be nice if someone with your knowledge was working in the shop here.