OK ... I've ordered an eprommer from Hongkong ... should be a while to arrive. In the meantime I've re-tried with my old one, and I've taken lots of pictures. I'll break this up machine by machine.
The PC-D has the mainboard, a graphics board and a (I guess) SASI=>MFM harddisk controller.
The keyboard is non-standard, warm start is rather PC-style with Ctrl-Alt-Löschen (which is of course delete) Pictures Siemens PC-D