It indeed was the 397 BG, (by more or less co-incidence) the leader of box II, flight B, dropped the bombs on Doetinchem following their ‘failure’ on Schermbeck. This was ascertained in 2015 and was published in the (local) newspapers (18th and 24th of March 2015, see also WIKIPEDIA (
https://nl.wikipedia.org/wiki/Doetinchem_(stad)), by chance also just before its 70-th anniversary. Locally it meant a lot, as it had been a question for nearly 70 years whether it had been an ‘on purpose’ attack (= requested by the resistance) or an ‘accident’. The consequence of an ‘on purpose’ attack could be that local resistance members might feel themselves responsible for the victims of the attack. My conclusions were simply that plane 8077 dropped the bombs by chance over Doetinchem on their way back to base. The flight leader did so even trying to drop them ‘safe’, although he could not prevent some of them to have gone out ‘armed’. The consequence was that 16 bombs (of the 28 on board) have been accounted for, 10 exploded at the time, 5 did not (and were removed) and in 1973 a 6th had been found and removed. This already proves that indeed most bombs had gone out un-armed.
As indicated, the other 3 planes after the happenings over Schermbeck did drop their bombs somewhere, and that is the last remaining part of the riddle. But where…? Somewhere thus suddenly 3 US Marauders dropped 72 bombs at around 17:08-17:10 on the 23rd of March 1945 and this attack (I presume) thus also is still a mystery for those who are trying to piece together who dropped those 72 bombs at that time. There must be a match…..