66 dart LED prototype working for now
I might be able to help out with the LED controller. Sounds like you need a PWM with current control for, brake and tail regulation. I work with micro-controllers and it might be possible with an 8-pin uC, a couple mosfets, inductor and a few misc parts. Controlling the current will control the intensity. There will be no need for series resistors. Let me know if you have interest.
Years ago I had a yellow 66 Dart 270 convertible with 273 V8. Seeing you car brought back those good memories.