To reply to the multiplexer thought,
Yes, that is likely in the future if I continue to pursue simulation of this particular circuit.
To the transistor modelling,
The thread has been started. And yeah, I saw that transistor model in the tutorial. Talk about a ready-made canned "here's how easy it is".... Yeesh!
Let's just start with the thread and see where that goes, assuming it does. There may be some Multisim modelling guru out there, but I doubt it. Still I figured I should at least TRY to find such a person.