This is a Douglas Model 1867J, from 1954. This was a proposed DC-6 upgrade, equipped with Allison T56-D8 turboprop engines. It was never built.The Allison engines are much lighter than piston engines, so they were moved forward to keep the Center of Gravity unchanged. In addition, two fuselage plugs were addes for three rows of additional seats, along with a 12 ft wing extension.This model was presented in person by Donald W. Douglas to American Airlines CEO C.R. Smith in 1954, along with a proposal package. According to my sources, it is a unique model.
