GRJ, do you print the boards, or buy them ready for component installation?
One thought for LED usage, other than in trains, is to install a 25-amp rectifier and filter capacitor on a 10-12-volt transformer outlet (Z4000 has one fixed at 10VAC) and have a DC buss running around the layout to feed LEDs. If I were building from scratch, I would do that, but it's too late now.