Your thinking is headed toward the right track but still no cigar. I am looking for an airplane.
1. This aircraft was built by the producer of a famous fighter.
2. The subject aircraft was designed after the war the fighter served in.
3. The subject aircraft was designed in such away it could be sold to civilians as well as be attractive for military use.
4. This aircraft shared a feature with the most popular variant of the famous fighter.
5. This aircraft was manufactured by the original company for the military and manufacture by multiple companies for civilian use.
6. The military version was only used by two countries.
7. The subject aircraft was designed more than decade before the DH Twin Otter.