Also, the deck layout in the sketch looks to be for the spokes of the wheel, and not the rim.
Actually it looks like a pencil line too hastily drawn.
Also the Enterprise
was apparently much smaller in the beginning.
The "horseshoe" cross-section is a perfect match to the exterior pod in the top left and elsewhere.
What I really love about it is that it suggests artificial gravity by creating a centrifugal effect by means of rotation!
Here is the sketch at Trekcore: http://www.trekcore.com/specials/alb...etch_TT_K7.jpg