Finally – here it is, honorable ladies and gentlemen!
Yes, I know – you think that I am out of my mind! However, I am assuring you that 3 machines of this type actually were in active service even in 1941! 
I think I got it, my dear mr Librarian - the aircraft pictured is the Dornier Do D Bas, of which 24 were in use as torpedo floatplanes with the Yugoslav Royal Air Force, and presumably 3 made it to WW2.
What can I say, my dear Mr. Wingsofwrath? You have indeed set the standard by which all other surveys will be based. Bravo! 
And now - let us hear from you! 
Why thank you for the kind words, My dear Mr Librarian!
My turn then.
This should be fairly easy for the level of aircraft knowledge practiced on this board and I can hardly wait the next installment from Mr Librarian or the good Mr Sergej, since it’s the hunt I truly enjoy…
I am assuring you that those words are well deserved, my dear Mr. Wingsofwrath!
Besides – it seems to me that we do share that affection toward those wonderful Italian solutions like this Savoia Marchetti SM93.
After a long and busy day, our brand new mystery flyer is here at last:
Well then, do you recognize this machine, honorable ladies and gentlemen?
Hmm is it perchance a U.S. Navy R4D, the navalized version of the DC3 Dakota?
Alas – no, my dear Mr. Wingsofwrath. However, certain similarities with the good old Douglas Dakota are present in our case too. Our mystery machine definitely was originally designed for the civil utilization, but armed forces (equally air force and navy!) were pretty soon interested for this highly versatile and talented aircraft as well.
Could it be the Tachikawa Ki-54?
Unfortunately - no, my dear Mr. Sergej. Although our mystery airplane also posessed 9-cylinder, air-cooled radial engines as well, their capacity was significantly lower – only 185 HP apiece.
Can it by any chance be a Japanese Navy Hina-Zura (LXM), the Mitsubishi licence built version of the Airspeed Envoy, originally fitted with Wolseley AR.9 piston engines?
No, my dear Mr. Wingsofwrath. However, here is another highly interesting tip for you: the very same company that manufactured our “secret” machine actually produced those engines as well!
Airspeed Viceroy?
Alas - no, my dear Mr. Kiwimac. But I can tell you that our mystery machine surely is of European origin!
It was a long and grueling road, but I got there in the end: Potez 565 of the Aeronavale, the French Naval Air Arm,during testing on board the carrier “Béarn” in 1936.
The airplane was powered by two 185Hp 9 Cylinder Potez 9Ab radial engines, and pioneered the “Carrier Onboard Delivery” system as well as being the first twin engine plane to be flown on board an aircraft carrier.
It’s funny, but my first impression when I saw this picture was that the aircraft pictured is an Bloch MB 220, but then I started focusing more on nations that did use carriers during WW2…
Mr Librarian, I thank you profusely for a very nice “hunt” and here is the next mysterious aircraft:
Oh, it seems to me that nobody was interested for this truly intriguing little birdie: the WNF (Wiener-Neustädter-Flugzeugwerke) HV 11 - an flying boat derivative of the old Hopfner HA 11/33 amphibian envisioned for military purposes as a training aircraft for naval pilots.
Nevertheless, here are some highly interesting and utterly rare additional snapshots connected with this machine:
http://img177.imageshack.us/img177/1079/img481ig7.jpg
http://img405.imageshack.us/img405/5153/img483ph9.jpg
In the meantime, I shall present another, with a bit of luck more attention-grabbing and also sadly neglected machine:
Honorable ladies and gentlemen, I am most apt to embrace your offers!
Really feel bad need to overide Herr Librarian difficult quiz,.
but we need to keep this going
anyone can guess on this german’s plane?
Perhaps your mysterious birdie actually is our old acquaintance - Boeing B 17 Flying Fortress, this time presented in the Luftwaffe colors, my dear Mr. Gumalangi?
And please – don’t be so poor-spirited! I am only trying to present some sadly forgotten machines of the days gone by - that’s all. Look – here is another snapshot connected with our mystery-flyer:
I hope that this additional photo will be sufficient for your triumph.
Herr Librarian,.
The B17 was indeed belong to German’s Luftwaffe
My wild guess would be Cansa Fc20
Regards
You are on the right track, my dear Mr. Gumalangi, but in fact, a different, also well-known Italian manufacturer, produced “our” mysterious airplane, which - essentially - represented a multi-purpose machine, intended to grow to be a long-range fighter, a fast transporter, a light bomber and a middle-range reconnaissance aircraft.