Year Three's other outstanding Klingon episode, "The Day of the Dove", may shed some light on the treknology of TOS. Consider this passage, which takes place after all phasers become swords and the Enterprise begins surging forward into deep space out of control:
KIRK: Full sensor scan of the ship. Report on any movement by the Klingons. The Klingon Empire has maintained a duelling tradition. They think they can beat us with swords.
SPOCK: Captain, neither the Klingon technology nor ours, is capable of this. The instantaneous transmutation of matter. I doubt that they are responsible.
KIRK: Any other logical candidate?
SPOCK: None. However, if they had such power, would they not have used it to create more effective weapons and only for themselves?
Of course, this is probably not the last word on this subject. I find it hard to fathom how starships that use matter-antimatter annihilation to exceed the speed of light, transporter to "beam down" to a planet's surface, and phased particle beams as weapons cannot muster at least some rudimentary level of replication/transmutation technology.
That's not what I get from that. The phasers changed instantly
into swords. They weren't broken down into basic elements first and then recycled into swords. The Feds could easily make swords if needed, but from raw materiel and not from already existing phasers turned instantaneously into swords. There's a difference.
In "A Private Little War" Kirk asks Scotty to fabricate 100 flintlocks. Certainly such an antiquated weapon wouldn't be kept on hand aboard ship "just in case." In "Patterns Of Force" McCoy is provided with the uniform of a Gestapo doctor within minutes---another rare and unusual item. In "The Cloud Minders" the inference is the Enterprise
can easily supply enough filter masks required for all the Troglytes. In "Return Of The Archons" and "A Private Little War" native clothing is provided before beaming down. None of those items would have been carried aboard "just in case."