By Star Trek VI (2293 or so), observed starship status charts such as the "Starship Mission Assignment" chart seen on a computer screen still show the USS Constellation as having her NX registry, NX-1974.
Registries are broadly chronological. The Excelsior is perhaps an exception, given that comm chatter in the early 2270s references the existence of the Entente, NCC-2120 . . . perhaps 2000 was held for the transwarp experiment ship that was rather long in development, which -- per my pet theory -- her unusual bridge controls with an updated style but TOS-esque color palette also indicate. Whatever your view, by 2285 the Excelsior was definitely NX-2000 and ready for trial runs, and by 2290ish the ship had received an update to NCC and was sent on a three year mission under Hikaru Sulu.
By registry, however, the Constellation must pre-date the Excelsior to either a large or small degree. There's no obvious reason to reserve the number 1974, after all.
This all tends to point me toward the idea that the Constellation actually hearkens back to the mid-2260s or so, and seemingly had a long and troubled development, and perhaps even a redevelopment. An obvious reason for this would be her significant size (three times the Constitution, compared to the Excelsiors at four times) and, more importantly, the quad-nacelle arrangement. I presume that the quad-nacelle setup, never observed on any previous Federation ship that I recall from the Original Universe productions, was especially difficult to perfect.
The Excelsior and Constellation classes both feature next-lowest registries in the 2500 range . . . the Repulse 2544 and the Hathaway 2593 . . . at an NCC rate of about 20 per year, 2520 would be twenty years after 2272, or 2292. By that time the Excelsior has been an NCC for a couple of years and perhaps the Constellation is just about done NX'ing, allowing for the Hathaway (an amusing name after a lengthy development cycle) to be built circa 2295.
(Also, If four nacelles are exceptionally more complicated than two, this may also help explain why nacelle pairs retain their popularity through the decades even as they grow to such massive sizes that the whole idea gets a little ridiculous (e.g. the Galaxy nacelles that are the size of a Constitution Class ship). Otherwise it would seem to make much more sense to have a larger number of some standard nacelle size, but this isn't what we see. Only the Cheyenne and Prometheus really go for the quad, as I recall, and even the latter is unique in that regard.)
Registries are broadly chronological. The Excelsior is perhaps an exception, given that comm chatter in the early 2270s references the existence of the Entente, NCC-2120 . . . perhaps 2000 was held for the transwarp experiment ship that was rather long in development, which -- per my pet theory -- her unusual bridge controls with an updated style but TOS-esque color palette also indicate. Whatever your view, by 2285 the Excelsior was definitely NX-2000 and ready for trial runs, and by 2290ish the ship had received an update to NCC and was sent on a three year mission under Hikaru Sulu.
By registry, however, the Constellation must pre-date the Excelsior to either a large or small degree. There's no obvious reason to reserve the number 1974, after all.
This all tends to point me toward the idea that the Constellation actually hearkens back to the mid-2260s or so, and seemingly had a long and troubled development, and perhaps even a redevelopment. An obvious reason for this would be her significant size (three times the Constitution, compared to the Excelsiors at four times) and, more importantly, the quad-nacelle arrangement. I presume that the quad-nacelle setup, never observed on any previous Federation ship that I recall from the Original Universe productions, was especially difficult to perfect.
The Excelsior and Constellation classes both feature next-lowest registries in the 2500 range . . . the Repulse 2544 and the Hathaway 2593 . . . at an NCC rate of about 20 per year, 2520 would be twenty years after 2272, or 2292. By that time the Excelsior has been an NCC for a couple of years and perhaps the Constellation is just about done NX'ing, allowing for the Hathaway (an amusing name after a lengthy development cycle) to be built circa 2295.
(Also, If four nacelles are exceptionally more complicated than two, this may also help explain why nacelle pairs retain their popularity through the decades even as they grow to such massive sizes that the whole idea gets a little ridiculous (e.g. the Galaxy nacelles that are the size of a Constitution Class ship). Otherwise it would seem to make much more sense to have a larger number of some standard nacelle size, but this isn't what we see. Only the Cheyenne and Prometheus really go for the quad, as I recall, and even the latter is unique in that regard.)
... YMMV.
