72 overcharging

Unless we've missed something along the way, I don't know. one last thing you can try.......get the thing as 'normalized' as you can that is fully charged after starting, and warmed up. (VR is temp sensitive and some are temp compensated) Now, with the engine running at fast idle and all accessories off, measure V between the VR IGN terminal and battery NEG post. Also measure between VR IGN and the VR mounting flange, see if there is a difference. Last, after measuring these two points, measure across the battery and double check

If the VR measures closer to correct, that is around 14V to the VR case, you still have a voltage drop problem.