C.E. Evans wrote:
To me, it's much easier to call it what it was onscreen--a redesign of the ship. And I think about 9% of the original was retained (to match Decker's claim that Kirk didn't know the redesign a tenth as well as he did).
It does make you wonder what the 9% is
exactly, though (I agree with your earlier assertion that it could
be as simple as the 'skeleton' of the old ship).
One thing which puzzles me is the general lack of other Constitution refits out there. Obviously the later 1701-A came from somewhere
(theory being it's a renamed other vessel), but my impression of the TOS movies is that it always seemed like Enterprise was nearly the last of her kind, maybe only one of a couple Constitutions still in service... indeed, if Admiral Morrow in STIII is to be believed, Starfleet has definitely taken a shine against the Constitution Class.
Obviously the Excelsior project was ongoing, but even aside from that the rest of the fleet is depicted as other classes, all of them evidently from the 'post-Refit' era. Which really stands out compared to TOS, where most of the fleet seemed to be made up of indentical sister ships to the Enterprise.