ALLEN - I think you are entirely correct on those voltage regulators, two windings & relays. Yes, the V/R could make the charging fluctuate.
And if you think the 30-40 yr old amp gauges were bad you should hear the failure rate on the new ones!
About ten yrs ago I had the whole steering console off my 129 to have Dad do some repairs. I was carrying out to the shop to install, walking on my concrete driveway and stepped on an icy spot. My feet went out opposite directions and down I went. I managed to keep the console from crashing into the concrete, but the jolt was hard enough to knock the needle loose from the mechanism. It still was attached but swung back and forth as I moved the console side-to-side. It was brand new!
And if you think the 30-40 yr old amp gauges were bad you should hear the failure rate on the new ones!
About ten yrs ago I had the whole steering console off my 129 to have Dad do some repairs. I was carrying out to the shop to install, walking on my concrete driveway and stepped on an icy spot. My feet went out opposite directions and down I went. I managed to keep the console from crashing into the concrete, but the jolt was hard enough to knock the needle loose from the mechanism. It still was attached but swung back and forth as I moved the console side-to-side. It was brand new!