I really am dumber than I look. Brett's and your replies allowed me to think straight instead of having alternator on the brain.

First I eliminated the alternator and regulator as problems by making three simple tests with a voltmeter Won't go into detail here as there are numerous web tutorials.

Next I visually checked the fuses. Seemed OK. Then I put the driver's seat back, got my flashlight and started looking up into the dog's breakfast of wiring that lies behind the dash. Not that I've memorized it, but I didn't see anything that seemed problematic. But something called me back to the fuses. Perhaps it was the pain caused by that horrible seat adjustment knob which sticks right into your back when you try to do under-dash work. Next time that seat is out I'm going to see if I can switch the adjustment mechanism to the other side.

Reading the actual circuits being fused from the little plastic cover (yes, still have mine), I saw that one covered the instruments and turn signals. I've replaced all but two of my ceramic fuses with Buss cylindrical glass fuses with pointy ends...yes, they make them, but they are awfully hard to find... One which wasn't replaced was the 5A in question. It was hoary looking, probably original to the car. When I pulled it out, the metal part fully separated and I knew I had solved my problem. Just didn't catch it on the visual inspection.

That was easy. But without your guys help I bet I would have pulled the alternator and had it bench tested somewhere. Thanks. Now, if i could get the tach to work with my new MSD Blaster Coil, my 1800 world would be momentarily perfect. But that's a whole other thread.