The archive with the disks, photos and ROMs is on the FTP now.
Correction to the boot commands: From what I learned on the phone today:
For an installation floppy of Prologue for the "D" you need to type "B:0,100"
Other Prologue floppies start with "B:0,80", reading the OS from sector 0 on track 8
CP/M on a Z80 machine is started by (CR), on an 8085 (of which we have no example) with B:0,1
The guy who kindly offered to let me read in his stuff goes as "Aquarius" on the German VzEkC forum but might chime in here as well soon.
At least one of his Boss B Z80 is operational, so he can give valuable insight into the machine.