OK here's the wiring schematic I used....
a few notes: it's not terribly elegant... and I never did quite figure out how to get rid of the accent LED latching switch. The master power switch can be replaced with a kill key type system if you wish.
Oh and apparently, Tim no longer sells the 3W LED driver V2 in the store - probably cause he's busy trying to design something better.
If you'll notice, I have the activation momentary switch located right next to the accent latching switch, so it's actually not all that hard to turn on both one after the other. Again, not terribly elegant and for that I apologize.
One last thing, the tactile momentary switches that Tim sells in the store can actually turn on both the hasbro board and the LED driver board at the same time - just have to get the wires correct (I think it only works one way). Also, you don't need the clash sensor on the driver board since you now have the accent LED going through the NPN.