OK. I put in a mechanical oil pressure gauge.
Cold, the pressure starts at 25 @ idle. After warming up, the pressure settles to about 6 @ idle.
After seeing this. I changed the oil, and put in straight 40W -- no change in oil pressure behavior.
So what's next. The new oil pump install? I checked the ford dealership, they quoted me $575 for parts/labor. Ouch! I suppose I'll try it myself.
Daniel