Looks great! looks like you nailed the design of the "vertical warp core" (or whatever). Although the "flanges" around the bottom of the pipe should probably be around the top as well? As you probably know, the big red "struts" of this set piece were left over from the support colonnade of the pilot ep's circular briefing room, and the central "core" was also seen (as two seperate pieces) as columns in the phaser room set in "Balance of Terror".
This same set piece (the column) was also used again in "The Devil in the Dark"
as part of the pergeum reactor, where the ends were spliced back together where it had been cut in half, after which it appears yet again in the Constellations' engine room in "The Doomsday Machine"
(in a similar spot on the far right of the set, looking aftward. Maybe these referances can help you narrow down the "best look" of this thing, although what you already have is superb!