Robert McCall Space Ship Design P1

My latest project based on a Robert McCall painting (Robert McCall who did many paintings for NASA and thus inspired me to do this, also my attempt to do a design not based on Star Trek, Star Wars or anything else from the wide world of TV Sci-fi, this is fun as I have something of a free hand.
While I have worked out a scale to suit myself, I have no idea what Mr McCall had in mind so, here is my scale so far using a deck height of 9 ft. McCall 6