Entex Select-a-Game (1981) - some info needed

[phil_consollection]

4. Successor: I read about a successor to the Select-a-Game which exists as a prototype. Info on it is sparse. Can anyone advice?

I found some reliable information on that one:
http://www.handheldmuseum.com/Entex/...ameMachine.htm

For the other questions, any advice is still welcome!