Just to be clear, I don't think Grissom is an older design based on some notion about STIII originally being a prequel (I'm pretty sure it was STVI that was at one point headed in that direction, not III) I just think it's a fun idea for a retcon that rather neatly explains some of oddities regarding that class.
Exactly. When I wrote the essential analysis one year ago, that was the inspiration, and it's only during the discussion in this thread I gathered further inspiration on behalf of that idea.
@ Tomalak & Dukhat
I think the Excelsior
prototypes have a noticable retro-look which is rather the total opposite of what the final design looked like on film. And an NCC registry beginning with "14"?
ILM was a third-party-contractor, so if you want to keep the story a secret, you got to make sure that it's not leaking at the end where you don't have control.
And last but not least, the "Tauntaun lizard" is a good example that the communication between the people involved in such a blockbuster production is not necessarily as optimal as some of us outsiders do assume or want to believe.