It is damn difficult, because Trek cast a shadow over what came after it, albeit perhaps not as much as Star Wars. So I think you throw up the NASA stuff on the "don't wall," but perhaps you also throw up the saucer/nacelles as well. OTOH, since the OP posits no ST in the 1960s, maybe you end up with them anyway.
And you look at things like the newest tech and science know-how to determine what your ship could look like and how it could work (i.e., perhaps it is constructed of metamaterials
and uses a form of Alcubierre drive
And do you keep the aviation nods that MJ included?