The Burnelli machines had an airfoil shaped fuselage; some indicate near 10% of lift in a 21 century airliner comes from fuselage; 'Flying Wing' concept is old, and still attracts many; bottom of SR-71 looks shapen as a high speed race boat; at very high speeds, air is thick, not as a brick, but as 'marmelade', it's a Reynolds Number affair, this figure, you know, expresses relations of inertia and viscosity forces inside a fluid. 
Would a flat bottomed fuselage add even more lift than the regular round section, increasing the overall fuel economy of an airplane? Does the concept deserve Aerodynamic Wind Tunnel testing? Blessings +  
[![Proposed shape for fuselage, fins may act as 'Winglets'][1]]



  [1]: https://i.sstatic.net/wyrf4.jpg