Anyone Running A Mechanical Voltage Regulator 67 Dart 273 2bbl

I have a question for anyone running a Mechanical Voltage regulator (Alternator).

I bought a used mechanical VR for way less than they go for NOS. The internals look amazing, contacts not burnt, nothing corroded inside, in fact, except for the cork gasket the insides look brand new (OEM new not recently replaced new) I assume it has never been tampered with, no signs that the cover had ever been off.

Question...

How much fluctuation should the ammeter show at idle? with my aftermarket electronic VR the ammeter is steady at idle but with the mechanical it fluctuates, not a lot, but enough that I was concerned to leave it in place. Charging voltage at the battery was good, a tad higher then the electronic VR but nothing that concerned me.

Thanks