Looks like Ken got the right plane so it's Ken's turn. As for some of the clues, here's what I was looking at:
1) It was an unsolicited product designed as an upgrade to a proven combat aircraft It was actually designed to replace the Bre.5 as the designer,who designed both, didn't like the pusher design
2) It was used by several nations for over a decade after the end of hostilities(this was yesterday's clue)
3) It was used as a multi-role aircraft It was used as a scout, bomber, fighter and float plane
4) It was a two seater with an innovative design feature It was one of the first, if not the first, to use welded steel and aluminum tubing instead of wood for the internal framing
5) It was a two-bay biplane
6) It was a "tractor" style aircraft(the Bre.5 was a pusher)
If you would like to read more about this airplane, Ken's second link was what I used as a source document