I opened the original Ford container for a NOS voltage regulator early this year. I assume the container was sealed 55 years ago. It was in a FOMOCO labeled container, not Autolite, not Ford, with service part number C3DZ-10505-A. That part number is for a 6 cylinder VR (170 and 200 CID engines) with a generator. The date code is 3B26 (1963, February 26). That is based on the FOMOCO label. The marking is purple ink, about 24 point type (0.330 inch tall). The part number stamping on the VR is C2DF-10505-A. Its color is a flat, dull yellow. Its overall measurements are 1 9/16 X 2 13/16 inch. The word "REGULATOR" appears to be 12 point type.
Pic 1 - The VR and original container.
Pic 2 - Overall picture.
Pic 3 - Stamp.
Pic 4 - Date code location.
Pic 5 - Date code detail.
I posted this as a possible guide to period markings of early voltage regulators.
Jim