Well folks, I refrained to start a new topic on this since the info I found till now are limited to this draft. Anyway, this is a never seen before project by SIAI (not yet SIAI-Marchetti) from 1937 for what looks like a fairly long-range 40-seats plus mail transport. What you are seeing is research still pretty much in progress. This design seems unrelated to the SM-95, a four-engined version of the SM-75, which was built during the war and progressively enlarged (first versions 24-seater, later, post-war, 40-seaters). Only point of contact are the engines (Alfa 126 RC34s) and the general shape of the wing (which SIAI used again and again, progressively going to higher aspect ratios). The nose of the SM-95, for one, was pointed, since the fuselage was the same of the SM-75 minus the third engine, substituted by an aerodynamical fairing. The integral nose of this design is a real exception for SIAI. The draft, which lacks data except for dimensions, weights and fuel, seems have been reworked later (several years later, during the last years of war, from hints I have) by Alessandro Marchetti and added a number after the S. (don't know if it is visible from the image, but on the original is very clear, it's a "94"). The hand-made sketches point to a still more aerodynamically refined shape, that I think was the prelude for something very radical that AFAIK is known only in model form. But this is another story from a time later than the time-frame of this topic. Enjoy and forgive the verbose preface.
