ST - Scout/Excort Refit

in the late 2260s, a major update and refit package was developed for the scout/escorts https://www.artstation.com/artwork/dyeEW1 and they began bring flights in to drydock. this plan included major overhauls of the propulsion and power systems, the addition of another narrow corridor ring and compartments, and slight expansion of the hangar deck. the phasers were replaced with modern, paired, units, and the torpedo launcher also replaced with dual systems, making it almost the equal of a Saladin-class destroyers in terms of firepower, at least in the forward arc. the additional space afforded by the saucer expansion meant more crew spaces (as cramped as they still were) and stores, and a matter transporter system installed in the space occupied by the original torpedo room.
the final piece of the regime was a new surface coating over the formerly bare metal.

unfortunately, a fair number of the vessels had been nursing major structural and systemic faults since the war with the klingons in the previous decade, where many of them had been pressed into service in roles they were not designed for. in these cases, it was decided that it was simpler to build new ships to the new plan rather than refit, and while a number of those were also built, ultimately it was decided that a new ship for the purpose needed to be designed, and the bulk of the class was retired to mothballs or the scrapper.