Larry, yes, 12.6 sounds about right. My experience is that mostly 12.2 to 12.7 is normal. Gettin' towards 12 is asking for the car not to start at 12 or below. Glad to learn you diagnosed your bad voltage meter and that you weren't gonna blow anything up on your car from excessive voltage.
'58HT and '48 Dodge Panel in MN
Thunderbird Registry #3810 VTCI#7652