Dave,
Congratulations. It does sound like the voltage regulator might be the culprit. I would make sure the wires from generator to VR are in perfect condition. A '55-'63 Chevy truck uses a 12 volt, negative ground regulator in the 25/30 amp output range. Standard Motor Products # VR-20 is the number for that regulator.
Be sure to follow the instructions with the regulator on polarizing the system. I'll drink an O'Doul's and toast your success.
Stuart
