@All - Good finds on all the links.
I'm leaning towards the very tall ceiling after looking at the two screenshots. In the middle of the ceiling would be lights and framework that is barely out of shot. (Actually, we do see a piece of equipment, perhaps a spotlight, angled in the WNMHGB shot.) Above that would be the sensor gear in the above. In all likelihood it wouldn't be a window.
I don't have a problem for the framework to come down a bit by the time of TMP as more gear is put in above the bridge
I'm quite willing to fudge the layout if it makes sense to do so. My "Thermian" procedure goes like this:
1. Make it screen accurate if it is visible, even if it does not match the Designer's Intent.
2. If I had to guess (because it was never shown) then it would need to match the context of the series as much as possible.
3. If I had to fudge (example: curvature of the hallway) make the change as minimal as possible. (example: I kept some of the curve in my secondary hull layout. But for the saucer, I recognize that the curve would change depending on how far out the hallway would be from the center so fudge