How many are you able to transport, Chris? Knowing that might influence requests.

Of your suggestions the only one i would consider mandatory is pica AND elite, with possibly an example of the European 11cpi.

Interesting consideration: I was once involved in an automobile museum and a major discussion revolved around where the emphasis should be: the exotic models for their obvious pizazz and dreamy draw for the public vs the more common models that illustrated the everyday experiences of the times that most museum visitors would be able to relate to, that gave them a feel for how their families lived back then. Obviously, I came down on the side of the relatable experiences....

So, if you expect more experienced typewriter aficionados, then the uncommon ones; if more first-timers, then the more regular ones. In either case, though, a mix of vintage (which is probably what people expect) with colorful streamlined ones (they likely actually used newer ones in college), to show a century of "progress".

Hmmmm, I'm beginning to see your problem :-)

Have Fun!