that charging rate is too high. I'm thinking this 2nd electromechanical reg is the problem, a considerably way less 2nd choice would be the alt. I would certainly want to get an electronic reg which most parts house types are now (have no wire wound resistors on the bottom side of it) & a Wells 706 (iirc) was the last electronic one I got but it dont look OE (if that is critical). For sure the starting issue ain't a lack of voltage but it is critical to get this dealt with first as that high of voltage will fry (or significantly shorten the life) of bulbs and any electrical component that is "on" while it is charging that high. As said jump from the batt positive post to the "ign" terminal on the reg but your (posted) voltage drops are about as perfect as I have ever seen & a voltage drop might not be the issue (easy/free to check). I'm assuming the reg is grounded well since it has been changed & confirm the block is grounded well to the firewall/batt neg post. Backing up a bit I'm assuming you have a 2 field terminal alt with one terminal grounded.