Considering the instigator of the refit was Doug Drexler, I'd be surprised if there weren't deckplans lurking online already...
ps. and stealing BSG's 'retrotech' justification when totally unnecessary = super lame. The NX just looks more high-tech to the 80s-90s Ron Cobb/Syd Mead generation; but JJ's Enterprise looks more 60s than the original. Look at the iPhone; the future looks like the future again.