Originally Posted by riorust

Since you have a replacement voltage regulator, why not try it? You can tie the brushes back with dental floss, install it, cut and pull the floss out. Once you get it started, drive to an auto parts store that can test your battery. My VR went bad and I was getting 13.25 volts at idle, but it would drop to 10 or less at 2k rpm, its a cheap test, and if it is your battery you won't be any worse for changing the VR.

That's my 2 cents