|Images from Gene Gurney, The War in the Air, Crown Publishers 1962|
The Tupolev TB-3 first flew in late 1930 and about 800 were built in the next few years. It was considered obsolete by the time WW2 started but the dire circumstances of the Russian war effort kept them in service. By the end of the war, only 10 remained.
Or perhaps; incredibly, 10 still remained.