I was rebuilt by local guys that have a great reputation. I believe it is original to the car.
They might have used a heavier stator than original spec. Rebuilders do this, especially independent shops who rely on a good local reputation to keep business. Try measuring its high current output with full voltage to the field. Is this a 60A alternator? Don't be surprised to see 72-80 amps output from it if its originally an OEM 60A unit.