The "Meteo Fleet", is a series of TOS-era ships I did up from 2007 to now, which have their own unique features and growth, and have, with FASA, SFB, and occasional other ships, become the bulk of the Eta Universe TOS Fleet, to help explain them, and what occasional fragments you find of them (anywhere), I have compiled some synopsis here:
Scout, Juliet Cesario-Class-
This was a newer Class, intended to take the new Saucer-Sections under development since the early 2230s, and extend them, as well as make use of Andorian Warp Geometry, and to become a mass-produced Scout Ship, to expand Starfleet's reach, and to increase the High Warp-capable ship count, to accomodate the development of Duotronic Computers, and Breaking the Time Barrier. In 2244, the first of Six ships using the regular Registry Range were developed, and due to anticipation of mass production of some classes, an additional Twenty-one ships were launched using the NCC-LetterNumber Range, and they performed as a strong support element of the Galaxy Exploration Command.
Destroyer, Louisiana-Class-
This Class's Prototype was the first vessel to use Duotronic Computers, to great success, and launched in 2243, with an average Destroyer count of 18, serving typically in Three-ship squadrons along the Neutral Zone, along with the Cesario, they were deemed too impractical to refit to 1X, being old or small, and soon to be replaced by the more numerous and more advanced vessels being churned out by the expanded production yards, and served much of the way into the 2270s, then retired.
Heavy Escort, Carlin-Class-
The Carlin-Class was highly successful at establishing the Heavy Escort Hull Classification of Fleet Combat Vessel, and it's extra storage was highly beneficial, making them useful in odd jobs after being prime fleet units in the Four Years War, and unlike other Classes, they were considered worthy to upgrade to 1X in the 2270s, the last retired in 2292, a decent use of the new advances.
Patrol Frigate, Tacoma-Class-
The Tacomas were an older Class, from before the Time Barrier was broken, and made use of better Atmospheric Entry than most Classes, and more Laser coverage than most other ships, the vessels performing fine in the Four Years War, and retired in the late 2260s and early 2270s, also deemed too impractical to upgrade to the tech pioneered by Montgomery Scott and Helmut Albrecht.
Destroyer, Patton-Class-
The Pattons were an older Class of Destroyer, using a new NCC-LetterNumber Registry Scheme, by design administration, anticipating mass-production of smaller/non-combat classes, and although this did not hold true for the Pattons, where only an average 20 were built, they performed as Atmospheric Entry Vessels, and fought in the Four Years War, retired slightly earlier than several other classes, viewed as obsolete, and an archaic relic of Decker and April's Heady days.
Monitors, Sargasso Gemstone and Iron Oyster-Classes-
Both older classes of Monitor, developed in the 2230s, and functioning as the early Station/System defense ships, helping Starfleet to perform at longer ranges, and slightly less spartan than most late 22nd century vessels. They were gradually replaced by the Fenlon and Callus Classes, and were hideously antiquated, even by 2260s' standards.
Freighter, Crater-Class-
The Crater was an essential UFP and AOFW Design, helping to provide non-combat duties, alongside the Pershing, Independence, and Ptolemy-Classes, sometimes fitted with a Stardrive, and used in auxiliary combat roles, although this wasn't at all significant.
Battleship, Greenland-Class-
A plan to have a "Great White Fleet" of the 23rd Century, the Greenland was to have doubled Constitution firepower, although due to a few problems, like inflexibility compared to many vessels coming online at the time, low warp capability, around that of the higher-end stardrive vessels, and too expensive, the Greenland was abandoned, and sometimes documented, one of the strongest 'what if?' notions of the time.