Why it has Firestone written on the side, I don't know
"G and A (Glider and Aircraft) Division of the Firestone Tire and Rubber Company started work on the light tandem two-seat GA-45 design in 1943.
A first prototype was designated GA-45C and first flew during 1946. It was powered by one 135 hp Lycoming O-290-7.
The GA-45C was evaluated by the US Army under the designation XR-9B (later XH-9B) and had a 28 ft (8.53 m) diameter main rotor.
In 1946 the G and A Division became Firestone Aircraft, and a second aircraft was built as GA-45D, intended for the commercial market.
thanks for the info Steve!