Hello all,
Replaced the thermostat.
The symptoms were the radiator fan motors would run up to 3+ minutes after the engine was shut off even on short trips and cooler weather.
For the forum, I deduced that either the pump or thermostat had failed. I weighed all the comments about the plastic thermostat housing and plastic pump parts and considered replacing it all once, but with my recent experience with the cam tensioners being in excellent condition, I just replaced the thermostat.
Also, checking the radiator hose for temperature after a drive, one side was always cold when compared to the other side.

Worst part was catching all the fluid as it cascaded down the front of the engine when the hoses were removed.(I removed the two largest, probably could have left the one that attaches to the manifold in place, but it would have been a torrent of fluid when I pop out the thermstat.) I lost about 50 ounces.

Three bolts, clear access, remove and replace. Very easy.
Put the old one in water with a thermometer and raise the temperature. It did not open at all even a 100C.
Parts cost $16, over the counter at local autoparts store. Took me 90 minutes.

Results - no more running fans after driving,

RR

 

Should have done the water pump, stumpy hose, and maybe cross-over, as well .

 

I really thought about changing out all three. I even had a wrench set aside for bending. The car is just in immaculate condition, cleanest motor I have ever work on. After replacing the secondary cam tensioners which were in perfect condition, I opted out of replacing all the coolant parts. Maybe being garaged in New England and low milage hasn't impacted the components as in hotter areas. Time will tell.