12.7 VDC is good for just the battery
14.7 running is good, showing the alternator is charging
the swing and the lamp on . . . not good
did you ever say if you have the original "mechanical" regulator, or a solid state, or even a built into the alternator
here is a drawing of the original charging system, showing the intial energization of the alternator field through the lamp and then the switch over to self excitation once spinning. notice the relay that uses the center tap of the stator 3 phase windings