I'm wondering if there's any fan art floating around out there from before the 1975 Franz Joseph Technical Manual or before The Wrath of Khan. These were (to my knowledge) the first instances of Starfleet ship configurations other than the Constitution class, one being published and the other on-screen. (I'm ignoring the original version of the Aurora that used the Tholian ship with nacelles, although that wasn't specifically Starfleet anyway.) I'm curious what the thinking was in the fandom as to what a different Starfleet ship might look like at the time, outside of any official (or semi-official) influence. These days, there's decades of information available, and we can tell instantly if something is Starfleet by its design language. Back then, there was only the Enterprise/Constitution.