When I met with McCall, I asked him if, when he designed the look of spacecraft, he made schematic blue-printish sort of drawings to lay out the various functions of the vehicle. He laughed and said no way, he would just improvise the painting as he went. But some of these drawings show that he leaned that way for certain projects.
Some of these spacecraft seem entirely believable. As humanity moves into the future of space travel, I hope engineers might look back to some of McCall's concepts and think, 'hmm, with a little work, this just might work.'