IG-88, the threads aren't too deep you need to drill some space out on the back like this (I ripped the image from Retrofuture's thread it's not for those buttons but it's the same basic principle)
System01, thanks!
Retrofuture, thanks, they're actually playing Dragon's Lair in the Photo, but they hated it, the death sequences with all the skulls and bones really scared them (I wouldn't have thought that) but they liked marble madness, Mario bros, pacman, Donkey Kong It was a little tough the older one was a little possessive about playing so the younger one didn't get to play to much, it was getting past their bedtime