A month without a touch on this... where is that blushing smiley?
On Saturday, I finally got back to it and finished the bridge. You know why nothing seemed to fit? Because the filming set had the front window much less sloped than the CGI model has. That's why the grating could stretch all the way to the front and why they could put another floor level under it. Once I realized this, three options appeared:
1) Put the bridge floor rather low, so the gratings could be flush with it and wouldn't stick out into the window. In this case, there wouldn't be enough space underneath for the additional level, bridge ceiling would be about 3 m high and pilot's forward view would be nonexistent.
2) Put the bridge a bit higher, as the official blueprint suggests, and lower overhead part of the ceiling. That would look weird from the outside, pilot's view wouldn't be much better and the grating wouldn't fit under the window sides anyway (the center would be OK; this is the problem of these blueprints: they look perfectly plausible until you add the third dimension).
3) Put it even higher, so the front ortho view fits the series CGI model. This solves the ceiling and forward view problems and provides underfloor space for the airlock, but the gratings must be completely discarded.
n) If you can't tilt the window, tilt the floors
. Gravity is artificial and deck-dependent, so why not. Possible, but we all saw the floor is horizontal even when the ship had been sitting powered down on a scrapyard, so this doesn't count as an option.
At the end, I chose option 3 and then everything just fell into place. No screenshot to come, this part is unrenderable (several solids within each other with no chance of transparency, and the wireframe is rather complex).
Next to come in about two weeks: sensor arrays under the nose and detailing of the whole front part. Then some little detailing on the main engine and then... go unfolding! Hooray!