Came up with a simple but effective solution to the dark/unlit targets under the bat phone that looks stock and even flashes with the phone light:
Just used the LED off a normal bayonet LED, and soldered it to the LED under the phone. Then used double sided tape to stick the LED to the front bottom of the phone which hangs just over the lip of the plastic.
Trickiest part is getting to the phone and unscrewing it from underneath. With the phone position towards the front, just undo the turntable parts starting at the top until you get to the phone then undo all the screws holding the plastic. Then lift up the plastic and unscrew the phone from the bottom.
White looks great but could possibly use a red LED also.
Now to work out lighting for the TV targets - a bit trickier, but got an idea.