While I haven't been able to settle on a marquee idea, I did install wiring for the coin door lights. I set up a pair of jumbo blue LEDs (and resistor) to the +12 volt of the computer wiring harness.

The initial test of the wiring almost set my computer on fire.

I wired everything together, soldered all the connections and even setup heat shrink tubing to cover all the solder spots. But I didn't want to activate the tubing until I had done one final test. So I made sure all the tubing was in place and plugged the circuit into the harness. The blue lights lit perfectly. Cool.
I decided to pick up the LED end to shine the light around... this is where things went... poorly.
The tubing slid away from the joint closest to the harness, this created a short on the +12 volt line. The door lights were plugged into a daisy chain of wires for the case fans. Several of these short wires grew bright red, the insullation melted/flaked off and smoke started pouring from the wiring.
After a moment of surprise, I unplugged the computer.

Fortunately, no real harm was done, I rewired all the case fans and made sure the shrink tubing was secure before testing the coin door lights again.