OK, some more data for those who think I'm not actively trying to research the cooling too...

I managed to get the fans out by only draining the coolant and removing the top hose. So I refilled it and went for a ride (78F and humid at the present).

A very strange phenomenon, maybe someone can tell me why: Warmed it up a bit to 160 on the gauge, started driving, temp went to 183 and t-stat opened as expected. Fast drop to 165 as the cold coolant in the radiator hit the engine, then gradually back up to 182. I drove a couple of miles at 30 mph and it stayed on 183. Thought I had my answer for sure (airflow obstruction). But wait, there's more...

So I turned around in the driveway (10 sec. max) and while I was doing that, the temp popped up to 190. Started down the road at 30 mph again... and it would not come down below 188 in the next mile.

Made another 3-pt turn down the road, and it rose to 198. Another mile, would not come down below 196, so I drove back to the garage and shut it down! Went up to around 215 due to accumulated engine heat. I put the garage fan on the radiator and it's dropping slowly (the electric fans would normally kick on and off a few times).

The gauge does not seem to be sticky, so I have to assume for now that the temperature readings are real.

How on earth can it be operating steadily at one temp, but "bump" it a little while idling/stopped and it won't come back down? This is outside my area of experience and I've never seen this on any other car I've driven in the last 40 years!

And I know it's not obstruction of the airflow by the shroud since the radiator core is sitting there wide-open...