This is a fascinating picture:
— Paolo Nurra (@PaoloNurra) September 10, 2014
Some more information here.
The first B-17 to come under Japanese control was an B-17D which was pieced together from the remnants of other destroyed B-17Ds on Clark Field in the Philippines. The same thing was done to to two B-17Es on Bandung Field on Java. At the time, this was the newest model of the B-17 available. The Japanese were impressed with the simplicity of the cockpit for such a large aircraft. One of the B-17Es was used for a test bed for a captured Norden bombsight, coupled to the Sperry automatic flight control system. Also of great interest was the B-17’s gunnery equipment, especially the Sperry automatic computing gunsight. The May 1943 issue of Koku-Asahi was devoted almost completely to the captured B-17s. Nearly every major component was shown in photos and drawings. Since the Japanese also had instruction manuals for the aircraft, no detail was overlooked.