After reassuring myself that I had checked and double-checked everything within the charging system, I removed and opened up the "newest" warranty replacement regulator, and I found the root cause of my issues. At the bottom of the cutout relay's pull in coil, the solder connection where it joins the strap for the contact point had broken away, causing the cutout relay to not close. It looks as if when they assembled it they didn't remove enough shellac from the wire prior to soldering. I cleaned up the solder end of the coil, re-soldered it, started the car and BAM, we were getting 14.5 volts to the battery side of the regulator. I ran outside and repeatedly screamed "I FIXED IT!!!" My neighbors were not amused. My son drove the car about 30 miles yesterday and all is well.
Dave your animated diagram of the voltage regulator is dead on, but you knew that. Thanks again for your reply!