[3] Six NA-68s ordered by the Royal Thai Air Force were seized before export by the US government in 1941, after the Franco-Thai War and growing ties between Thailand and the Empire of Japan.

The North American Aviation NA-50 was developed as a simple single-seat, low-wing, single-engined fighter for export.

The NA-50 Torito (Spanish slang for "little bull"), built for Peru, was a single-seat fighter design based on the two-seat Basic Combat Demonstrator NA-44.

The NA-50 was powered by an 840 hp (626 kW) Wright R-1820-G3 radial air-cooled engine that gave the NA-50 a top speed of 295 mph (475 km/h) at 9,500 ft (2,900 m).

The changes in the NA-68 included a modified landing gear, new outer wings, heavier armament, and redesigned tail surfaces similar to those adopted on later production trainers.