500 ohms - I figured that must be the size of can of soup. But according to this apparently not.
500 Ohm 10W Resistor Wire Wound 5% Tolerance | 016-500
I originally started with an all electronic VR that I believe came from ERA. When my charging issue popped up - and not exactly being a fan of solid state regulators, ignition systems, etc in old cars - I bought a mechanical VR and installed it. Neither one ever worked - so far. Alternator bench tested OK and puts out good voltage in testing. I still have the mechanical VR in it since I like being able to look at something mechanical like points and understand what is going on.