At the same time (late 1940s) Lockheed built and flew a similar-looking airplane: the single-propeller Starliner registered NX-21725.
Initially, Lockheed test-flew thier twin-Menasco power plant on the front of a low-wing Orion (?).
Lockheed's Starliner prototype was powered by a pair of Menasco engines mounted side-by-side in the nose, driving a single propeller through a combining gearbox. The pair of inverted, straight 6 Menascos produced a total of 520 horsepower. The first prototype Starliner had twin-tails, but was later modified to a single vertical fin.
Soloy tried to revive the concept during the 1990s by installing a pair of Allison/Rolls-Royce 250 turboprops in the nose of a Cessna Caravan, turning a single propeller through a shared gearbox. When the FAA refused to certify the STC, Soloy dropped the project to concentrate on converting light helicopters and Cessna 206s to turbine engines.
Odd that the FAA would not certify Soloy's twin-engined proposal when you consider how many thousands of multi-engined helicopters have two or three engines driving a single rotor through one shared gearbox?????
Most recently,, advocates of electric airplanes have proposed combining an electric motor and a piston motor to drive the same propeller through a shared gearbox.