Few electrical questions

Grounds. each bulb in the instrument panel has a screw beside it to provive chassis ground the the housing . Then the housing has mounting screws conducting the ground path to the dash. There should be a ground wire between the firewall and right rear of the engine block to complete the path. Somewhere around 72 or3 the factory added a ground wire from the neg battery cable to the radiator support which improved the path from body, headlights, park turn signals , etc..
as for the voltahe regulator, buying imported parts from your local part store does support that retailer, your local economy.