Semrau had three kills confirmed, possibly four but I'm not sure about his fourth one.
Concerning Morlock, I believe he is the only one (except one claim for Jansen) to have claims south of Düsseldorf. One way to find out is to locate one or more Lancaster crash sites. Those south of Düsseldorf could be the ones you are looking for. Also Jansen and Morlock both got a Lanc at 19.31, so one of these is certainly Morlock's (the one will probably be the closest location to his next kill which only two minutes later so he had to be very close and see his next victim while shooting at the previous one). By pinpointing one of these Lancs you would have a good lead.

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