It's obvious you've already made your mind up about the subject.
Actually, the whole thing started as a "What if" excercise. When I sat down and took the time to analyze the Oberth Class design in detail all these little hints - that could suggest otherwise (i.e. not a late 23rd Century design) - showed up.
I'm unable to see how
Blip could possibly arrive at the conclusion that my observations/alternate suggestions had been "refuted throughout this thread", on the contrary, a few more hints popped up.
So yes, I made up my mind about the subject because I see more hints suggesting an early 23rd Century design than a late one.
However, I personally don't find your justifications ... to be anywhere close to solid evidence of an older ship.
I presented the observable facts and interpreted these. You disagree with the interpretation, that's fine. I also never said there is solid evidence. But since we are talking about evidence:
Where is your evidence that it is/has to be a design of the late 23rd Century?!?
Fact is you have none. All you can offer is a widespread and apparently popular assumption that is neither backed by onscreen dialogue or monitor readouts.
You also seem to want to ignore my justification, such as the design having lots in common with the Excelsior study models.
I thought I'd be doing you a favor but since you asked for it, here we go. All the ST III study models show an obvious retro look with various extending fins at the stern of the warp nacelles which moviegoers and model builders usually associate with spaceship designs from the "Flash Gordon" and "Buck Roger" series from the 1930's, add to this the abundance of rectangular elements featured with the
Alka-Selsior. The design of "The Rocketeer" and (SW) Clone Trooper helmets are a testament to that design language.
Fortunately Leonard Nimoy realized that this was somehow not going where he wanted to and asked for a design change. IIRC, both the
Grissom and the Merchantmen vessel studies remained essentially intact.
So what does the Merchantmen vessel look like or resemble? Something between a horseshoe crab and a trilobite, one a living, one an extinct fossile but both with an undeniable archaic connotation.
If you feel that these ST III prototype models represent credible designs of technolgical evolution paving the way from the
Enterprise-A to the
Enterprise-D I won't be standing on your way, but I feel these qualify better as design studies for pre-TOS ships,
Grissom included (and regardless whether ILM thought ST III would be a prequel or not).
Bob