Read an article about building a Redbox either on the 2600 Usenet group or some other hack/phreak BBS probably around 1993. Went to radio shack the next day to buy the tone dialer and crystal. I messed up the solder pretty bad but it still works to this day.
I still have an old tone dialer I picked up in the late 90's laying around. I don't believe was one of the "right" models to modify and I never got around to seeing if it even could be modified. Guess there wouldn't be much point these days but its an interesting historical curiosity