I'm 100% convinced the Excelsior was detailed to be about twice her official size, not just by rows of windows but by their size too.
Here are LOTS of great pics of the Excelsior/Enterprise-B/Lakota model: http://www.modelermagic.com/?p=2932
Here are the pics I posted in the Oberth thread, about the bridge module and deck height failures at 1532ft/467m, using the Enterprise-B MSD as (an admittedly imperfect) reference. I chopped off the nacelle fins when scaling to the Excelsior's 467m size.
As you can see, the bridge module is very similar to what we'd see decades later see on Enterprise NX-01, with windows surrounding it indicating rooms or at the very least a service corridor. This bridge module was added to the model in STIV. There's also a TNG-style lounge at the rear. I used Strategic Design's 1701-A deck plans for reference, since the Excelsior/Enterprise-B bridge is a redress of the Enterprise-A's
Here we see the deck heights of a 1532ft/467m Excelsior compared to Leonard Nimoy's 6ft Spock. That's zero headroom, even with very thin decks.
From a thread about a year or so ago, I used the Enterprise-B MSD to determine the Excelsior's "true" size. I found that to have 8ft deck heights the Excelsior would need to be at least 622m/2060.6ft long. To fit the bridge module, larger even than that.