Alternator voltage regulator teardown and analysis

I just had my '68 340 Formula S restored and they used an 80 amp alternator with a Chinese made regulator. It bounces between 14 and 15 volts all the time. No steady output. I replaced the regulator with an old one I had, no markings on it, but the resistance between the two posts and ground was different and the high resistance post was the opposite one. I have no idea what the resistance should be, but the old regulator had smooth voltage output above idle at about 15V. As the regulator is a switching diode controlled device, I thought the regulation would be steady at least at one voltage. Time will tell if this works.