I chopped up one of those GameKing units and uploaded it here. I thought I could just do the silver one and recolour it to make the yellow or other ones, but it wasn't working well so I just uploaded that one for you to play around with a basic lay file. No bells, whistles, no animated buttons. Just quite simple.
If you want to do one for GameKing2 and GameKing3 I can get you scans of those units, should also have a blue (I think) GameKing1 somewhere.