Sorry for the delay.
I do have a brand new battery, and I even swaped it with my '87 300D incase I was sold a defective battery.

Some new observations:
Vehicle Off: 12.4 - 12.5V
Key Turned to Heat-Glow (All Electrical Items Off...Radio, Heater, Lights): 11.3 - 11.4V
Vehicle Idle: 11.8 - 11.9 V
Then:
20 - 30 Seconds after idling the reading jumps to 13.8V, even 14V.
OR
If I rev. up the throttle, it too will jump to the proper reading.

This delay before it jumps to an acceptable Voltage doesn't happen on my '87 300D when idling, instead it's instantanious. I believe this could be the root cause of my problems.

Any ideas???

Thanks.