Lighting dims question

[hangarb7]

Here is the deal. I have had this car, which was rebuilt in the early '90's ('30 Tudor) for 11 years

Same problem since day one, so I will tell what I have done and tell me if it is normal.

I have added ground wires to every light, including tailights. I have run a seperate ground to the generator and the starter ( a heavy braid on that). I have turned up the 6V generator so that it is now putting out 8-10amps at cruise, and -2 to -4 with headlights on. All lights at idle and cruise are fairly bright (I mean, you know what I mean). Output of gen is 6.8V. I have replaced the light switch with a new Snyders (excellent quality) unit. I have also completely gone over the wiring of the car and the joints are soldered and the wiring is according to the diagram.

I have not changed the original cutout since the battery is always up. Battery is the second one and is about six years old, however I have had this problem since the beginning.

Turn on the lights, but as soon as I hit the brakes, lights dim considerably. Also, with lights on (no brake lights yet), horn just says 'eeeeer', although I have a great horn without the lights on.

So, question.... any suggestions? Or is this normal ops?

Thanks for any reply