This is the pertinent David Shaw reconstruction of the original plans Matt Jefferies gave to Richard Datin to get him going on the construction of the model. A really remarkable bit of document archeology and interpretation by Shaw-
http://www.shawcomputing.net/racerx/trek_stuff/plans/jefferies_1964_sh1-preview.jpg
As you can see, no fantail and a second set of clamshell doors where decks 19 and 20 are located, and where the fantail hatch ends up going.
http://www.shawcomputing.net/racerx/trek_stuff/plans/jefferies_1964_sh1-preview.jpg
As you can see, no fantail and a second set of clamshell doors where decks 19 and 20 are located, and where the fantail hatch ends up going.