1) Looking for an aircraft
2) Could be considered "multi-purpose"
3) One engine...one wing...two seats
4) Same basic design...and was built by two different manufacturers...and had two alpha-numerical designations
(let me modify this statement...same alpha but different numerical)
5) This aircraft changed the way the parent company was viewed, by the powers that be, because it had previously been a rather small, might say obscure manuf.
6) Recip engine
7) Tandem seating
8) One version / designation was operated by 4 countries...
The other variant was operated by 7 because it was a bit more versatile
9) This clue is inspired by the post (elmshoot) above:
The inside of the cowl panels might be painted in young Bamboo / light Olive color, or a transparent blue / green
10) One version could have the pilot facing forward, and the rear crew member facing to the rear.
Another version could have the rear crew member also facing forward.
11) One might not have any armament at all...and another variant might have 2 machine guns and carry a few small bombs as well.