In 1952, the USAF issued requirements that became known as Weapon System 302A, calling for a supersonic intermediate-range strategic bomber. North American, Douglas, and Martin all submitted proposals, with Martin's Model 316 winning the design competition in 1956. Contracted as the XB-68, the bomber was expected to reach operational service by the early '60s. The XB-68 was unusually small given the requirements, coming in at a max takeoff weight of just over 100,000lb. It was of primarily steel construction, and was vaguely reminiscent of the F-104, with stubby trapezoidal wings and a T-tail. Power was to come from two J75 turbojets, and a crew of two was to be placed in a tandem cockpit. Plans called for a top speed of Mach 2 and an operational radius of 1,250 miles with a 3,700lb nuclear payload. Unfortunately, the project rapidly ran into issues with the inertial guidance bombing and navigation system, delaying the planned introduction of the bomber. Meanwhile, the Air Force was hit with major budget cuts, and in 1957, the bomber contract was cancelled.
In spite of the fact that Nash-Kelvinator never built the proposed flying boat in production, it did spend a lot of time and money on this wooden mock-up at its Milwaukee plant.
Flying-boat above is essentially the Sikorsky VS-44 and Nash-Kelvinator were going to build it under license. According to Wiki...
A proposed licensed version of the VS-44 to be built by Nash-Kelvinator, the JRK-1, was cancelled due to the availability of the impressed JR2S aircraft.[6]