The Johnson ROCKET 185 was a certificated production 3-seat aircraft produced in small numbers starting in 1946 by Johnson Aircraft, Inc. of Texas, as I recall. Later, in 1950-1951 it was built under license by Aircraft Manufacturing Co. which refined it into a 4 seat aircraft then known as the A.M.C. TEXAS BULLET 185.
The ROCKET was metal-framed with fabric covering and was a sleek low wing retractable gear speedster with some fatal crash history. Power was a Lycoming 185 Hp engine. Max speed: 207 mph, rate of climb at sea level initially 2,000 ft/min., ceiling 24,500 ft. It bore some close resemblance in flight to a WWII Bell P-39 AIRACOBRA military fighter.
The A.MC. TEXAS BULLET 185 was built also with a Lycoming of 185 Hp and certificated. Some confusion may exist between the two registrations/similar aircraft. It had 4 seats in an all-metal-skinned flush-riveted fuselage of similar shape, redesigned tail but somewhat different dimensions-wingspan just 28 ft. 0 in. vice the earlier ROCKET wing of 31 ft 0 in. Length was also different-23 ft 2 in. vice 21 ft. 7 in. for the ROCKET. Max speed was 210 mph. This aircraft also built in small numbers.
If the Johnson ROCKET is airworthy and in license, it could be a collector's sought item. A specialist aircraft appraiser might be of help to you. The A.M.C. TEXAS BULLET 185 version would be worth more, other factors similar re condition, etc.