I have focused beam LED headlights and LED tailights in my '31 pickup. I run the stock 6v generator's 3rd brush at its lowest output setting. This provides 4-5 amps above idle when the cutout points close. Even at its lowest output with the lights on, I still get a slight positive charge. It really is a great combination.
I made a short video showing this.
https://youtu.be/aAF18KGnH1k?si=1_9Dq51mxz0BH84G