Robert,
Read the pdf from here: Lucas Generator and Control Box tests.
It could be your voltage regulator contacts are fused closed. Anyways, clean all contacts.
I have a regulator where the swamp resistors are out of spec, so you can measure the resistances. The specs are on page 25. The swamp resistors will affect voltage detection.
Adjustment of voltage output will be done on car by turning the rightmost cam - the voltage regulation coil.
Regards,
Clive.