Haha! No, it wasn't, and yes, it undoubtedly was.

Ya know, sometimes I feel better not knowing the truth about my car. No Oil Pressure Gauge, No Voltmeter, No Water Temp, No Tach and No Worries. But to be honest, I am looking forward to the solution. I'll throw my hat into the ring with a *.W.A.G.(silly wild *** guess) of a Bad Ground. Although I can't see how that is possible since the sending unit itself is grounded to the block.

Nope, not a bad ground. Here, I'll give a big clue (since I already know the answer)...it wasn't an electrical issue.

spun a bearing? got a bad oil pressure sending unit?

Nope. Bearings are fine, and sending unit is fine, as proven after the fact (now!).

OK, enough suspense....I don't anyone to blow an artery over this.

The pan had what appeared to be a relatively minor dent from the
outside......however, internally, it completely closed the gap between the
pickup and the floor of the pan. At any kind of engine speed, the pump
would try to flow more than the impeded pickup could provide, and Presto!
Inverted oil pressure syndrome. RPM go up, oil pressure goes
down........RPM go down, oil pressure (now fully fed) goes back up to where
it should be.

I can't imagine how many "mechanics" I would have had to go through to have
this diagnosed if I had taken it anywhere, rather than fixing it myself.

Good one!

You're nothing but a big tease. :?

Ahhhh. So the pickup did have some sort of restriction. I was partially right, just didn't know about a dented pan Actually one of the first things I would have done was check the oil presure with a manual gauge, then take the pan off to inspect the pickup. I guess it really does not take much to give the pickup fits.