The "discovered" long-missing lend-lease Douglas A-20 that went down on a mountain ridge between Krasnoyarsk and Novosibirsk may be one that disappeared 6/12/1943. My research on this was brief and the list I have of A-20 accidents along the ALSIB Route that occurred in Siberia did not include AAF serial numbers but the list is not that long. I'll provide a link to the 2-page list and draw attention to item #86 (pilot-Ivan Ivanovich Zalomin-5th aviation regiment) and crew members listed #87 (pilot-Ivan Apkhipovich-5th a.d.), #88 (pilot-Georgy Ivanov-5th a.d.), and #89 (radio operator-Georgy Nikolaevich-5th a.d.). The A-20 while being ferried North to Alaska by 7th Ferrying Group (USAAF) pilots was almost always by pilot alone, in the early going there was often a flight-engineer/radio operator but became less frequent as pilots became familiar with the route. After the A-20 was handed over to the Soviets in Fairbanks, Alaska for forward ferrying by Soviet crews it was common for a twin-engined plane (A-20 or B-25) to act as lead-ship for a flight of half-a-dozen or more P-39 Airacobra(s) or P-63 Kingcobra(s). The lead aircraft would attend to navigational duties and were almost always crewed by more than the pilot, sometimes even transferring personnel between bases. Four on board might be slightly unusual but not impossible. Link to list:
https://www.flickr.com/photos/23057174@N02/15133486456/