Small suggestion for Mr. Probert: if the warbird was perfectly symmetrical, "vertical" and "Horizontal" would be meaningless.
Think of this: you could take this in a completely different direction and simply fold the gravitational fields "inwards", following the contours of the wings and the command module; this way, "down" is always at the centerline of the ship along the axis of flight. You could even describe this as a feature of the forced quantum singularity the warbird uses as a power source (what else, after all, would you use a gravity drive for, if not artificial gravity for the crew?)
That would maximize the amount of deck space on the design -- allowing the decks to "wrap" with the curved shapes of the wings and the hull -- while at the same time removing any "true" axis to the ship altogether. Like a real-world spacecraft, it has no true "top" or "bottom" and can come at you in just about any orientation it wants. It might even maneuver a bit like the Jellyfish from STXI; even in level flight, it can tumble and roll and bank randomly like it doesn't care which way is up.
In contrast with the obsessively vertically-oriented Starfleet, that would be about as alien as anything we've ever seen in Star Trek, IMO.