Moving past the breadboard...
I wanted to get the Control Panel off the breadboard at some point and kept trying different layouts on a big pcb. Then I realized that the project is likely to change over time, so why not build smaller "modules" that I could reuse if I went a different direction with the Control Panel.
I built the transistor output module first. It contains 5 simple TIP-120 transistor circuits and I added LEDs at the last moment on the input side. The input side is always at 5v, so it was really easy to pick a resistor voltage for the LEDs and not worry about it.
I then built a small module with the pots for the Liquid Crystal contrast and the analog gauge calibration.
I'm using LEDs here to test since the gauges are mounted in the Control Panel at this point.