XK-120 charging issue

To the JCNA XK brain-trust ÔÇô I could use some assistance with trouble shooting an issue with the charging system in my XK-120. Sorry for the length here, but IÔÇÖd like to give the full picture of whatÔÇÖs been happening.

It started on a drive back in December, when I noticed that my fuel gauge stopped working. The needle often sticks, so I tapped the gauge, but got no response. I thought maybe I had a gauge problem. Then the turn signals stopped working. When I got home and turned the car off, the IGN light stayed on. I suspected a blown fuse, so I checked the manual and sure enough, the fuel gauge and trafficators are on the same fuse. So I opened the bonnet and looked at the fuse ÔÇô it was good, but I noticed that the voltage regulator (VR) was VERY warm, bordering on HOT. Then I noticed smoke wafting up out of the generator. I got it disconnected to stop the smoke, and realized there was a real problem.

Over the next few months, I got the generator out and tested ÔÇô it bench-tested fine for charging. I also replaced the VR with a new one. When all the other unrelated tasks were complete, I got the car back on the road (in early May) and she ran great. Until a few weeks ago.

I was coming home one afternoon, and noticed the IGN light on full bright. I looked at the ammeter, and the needle was on the discharge side. So I turned the lights off (I normally run with them on for greater visibility ÔÇô making sure other drivers see ME), and the needle went to zero, and the IGN light went to a ÔÇ£low glowÔÇØ (for lack of a better description). IÔÇÖve driven the car like this a couple of times, and the charging seems to be just enough to keep the batteries on an ÔÇ£even keelÔÇØ, neither losing nor gaining charge.

Yesterday, I reinstalled the generator, having just had it rebuilt at a local specialist. They did find some issues with it (this is itÔÇÖs first full rebuild in 60 years!), and I was told today (by someone FAR more knowledgeable than me) that these issues could cause the VR to start to fail.

I do notice that when I step on the brake pedal, the ammeter needle goes to minus (as the brake lights are drawing current from the batteries). Same for the trafficator lights. But under normal operations, besides the ignition, the IGN light is about the only thing drawing any current (unless the gauges draw power somewhere/somehow ÔÇô I just donÔÇÖt know)

My thought/fear is that the VR (yes, the ÔÇ£newÔÇØ one) may be failing, but how do I tell for sure? What diagnostic steps can I take to isolate what the real issue is?

I am very ÔÇ£electrically challengedÔÇØ, so please feel free to treat me like a complete novice ÔÇô I wonÔÇÖt be offended!

Thanks!