I first came across your concept of the NPC-19 Interceptor Romulan War Destroyer on devientart and was moved to comment on it at that time. I started working on a pre-STTOS tome after watching the Star Trek Next Generation episode "Encounter at Farpoint". My idea was to set the historical events of World War II, in the early history of the Star Trek universe’s Earth Romulan War, as well as the years leading up to and following it. I used several TOS episodes "Balance of Terror", "Space Seed", and "Tomorrow Is Yesterday", mining them for their historic content of the early devised history of that universe.
What motivated me to post this was the amazing parallel of your design and one of my own ideas for a cheap, easily mass-producible space combatant. I took the design of the DAEDALUS Class ship, as my departure point. This ship was shown in the first “Star Trek Chronology” and encyclopedia, as well as a model shown on Captain Cisco’s desk in the ST: DS 9 Episode “Maquis”. I posited that the model was a stylized version of various prototype ships.
As we know, the original design the initial design was first depicted in a line drawing by Matt Jeffries, from Stephen E. Whitfield’s “The Making of Star Trek, and if memory serves, the drawing was captioned “USS Inverted”. I considered this was somewhat of a justification for the DAEDALUS concept being canonical as a pre NX, or CONSTITION Class saucer shaped primary hull. The model integrated the Star-drive/Secondary-Hull and Sphere-Saucer/Primary-Hull as a late war era design. Not to rehash the whole “Akiraprise” argument, but the needs of war and practical construction principles might lead to a simple, easy to build ship, just as Henry Kaiser’s “Liberty Ships”, and Casablanca-class escort carriers, as well as the redoubtable Canadian “Flower” Class Corvettes, all of which helped to turn the tide in the Battle of the Atlantic.
My design was to utilize the Star-drive/Secondary-Hull with weapons and some simplified control room added to the dorsal section just above the deflector on the bow. Such a “Gunboat” could be massed into “wolf packs” as USN fleet submarines did in the Pacific war. In the second part of my trilogy, the main character while recovering from injuries, points out the ability of such a design to function without the spherical Command /Primary-Hull.
I surmised that a cylindrical hull with warp nacelles pylons attached to the dorsal-amidships section of the secondary hull would produce a simple sturdy configuration and provide a liner flow to the impulse drive units at the dorsal-stern section of the cylinder. Weapons platforms as well as twelve Life-pods were located at strategic points around the secondary hull. Their interiors resembled the cramped and claustrophobic environs of World War Two era submarines, and corvettes.
I have to say that your presentation of this destroyer is quit an excellent interpretation of the original intent described in the short story of "Balance of Terror" that James Blish wrote in the Bantam Books adaptations of original series episodes. Indeed, in that story he described the war era ships as large cylinders in design. I wish I could create the quality graphics that you used to generate the artwork. Well done, and best of luck in your future endeavors.