Heck of a good guess MJD...the guys at Floyd Bennett are getting close to having theirs up and flying! Unfortunately not the one I'm looking for.
next clue
1. Designed in the mid 30's
2. The Boeing 247 and Douglas DC-2 were inspiration for this design
3. The last of the breed was retired in the early 70's
4. shared engines with other well known airplanes
5. there is only 1 that is potentially airworthy today
6. License built by 1 other country