Hi there
The story about the B17 in the Don was that it was stripped of all war-related goods (guns, bombsight,etc) and "donated" to the Don as a training aid, as it was more modern than anything else, in the Don.It came to a sad demise, after, it is alleged,an apprentice selected gear up and the whole lot flopped onto it's belly, narrowly avoiding crushing his classmates. It was then hauled to the dump and cut up.
Given the slowness of delivery of spares, the "windfall" aircraft kept the rest of the fleet going.
regards
GttC