I have been wondering about the close proximity of the two cockpits in this design, notably the airflow disturbance that would be generalted in the space between the cockpits as the airflow from each cockpit merged. I believe that the amount of air disturbance would cause both considerable drag and reduce the efficiency of the after propellors. Had this plane been built I would suspect that the dual cokpits would have been merged into one. There would be benefits in crew interaction as well, (as was found with the original cockpit arrangements in the Douglas C-74). Whether this would be side by side or tandem can only be speculation.
Flitzer, thankyou for your artwork, it does give an aprecaited perspective on these projects.