I think based on the straight corridor alone, J-Deck (deck 10) is the best bet.
Based on that description, I've roughed out what the layout might be and it seams to fit:-
Hmm. I just went through the material again, and it seems the bit about "no life support on the bridge, let's go to Main Corridor instead" isn't in the aired version I have on VHS, or on the chakoteya.net transcript. And no version of the script actually necessitates our heroes to be anywhere near the Bridge at any point of the episode.
Riker and Data don't really have a reason to try and reach the Bridge if they already know it's uninhabitable. Nor does it make great sense that the doorway that leads directly to the bridge would have this large computer monitor set right next to it. The one reason we might believe in proximity to the Bridge is the dedication plaque we see behind Data's shoulder - but those plaques have been seen in various locations aboard other ships, not necessarily adjoining the Bridge at all.
The "Main Corridor" (if that reference really made it to the air) could be a facility quite far removed from the Main Bridge, much like Main Engineering is. AFAIK, real-world naval vessels have a Main Corridor, too, denoting the central longitudal passageway belowdecks (although it's not necessarily on the centerline any more in modern vessels). And this corridor traditionally connects crew berthing spaces rather than important mission facilities. Our heroes might have beamed into the "communal center" of the ship, then - into an area where the scientists used to have their brainstorming meetings, next to their quarters. That lobby would have been a natural place for the dedication plaque, too.
If so, we once again have lots of liberty with the placement of these sets. But a corridor running the length of the ventral pod is a good candidate for the ship's Main Corridor...
I know the bridge doesn't match what we saw on the partial set, it's just a placeholder to see if there's enough floorspace. Plus I can't seam to find a floor plan for Ilea's quarters (I assume that was the set they used) so I gain I just dropped in rough placeholders.
The crew quarters where the naked corpses are seem to have the recognizable semicircle walls of Kirk's TMP quarters, although now with prominent support beams, and the far wall window/display seen in those quarters in TMP,
and the plain, smoke-glass sliding doors. It seems that apart from the beams, this set was used essentially unaltered, just sprayed with stage-frost.
When action moves to the shower stall where the dressed female corpse is found, I'm not sure that the set would be a TMP one recycled. Ilia's shower stall didn't have a sit-down computer station to the left of the stall door, and the angles of the wall segments seem wrong, too - the pieces seem to have been reassembled.
Timo Saloniemi