Thank you for posting these. (My apologies for not writing in German).
In the UK my highschool had a MAEL 4000 machine. This was donated to the school in the late 70s by Friends Provident Insurance company when they retired the machine. It was much older than your model, with some significant differences! Already by ~1980 it was very much obsolete. The machine was a single long desk, with disk and tape and console built-in to the desk. At one time it was in working order, although there didn't seem to be anything useful to be done with it and I never managed to program it to do anything useful... in the end, I regret, we trashed it (kids!).
- The main output was a typewriter (hardcopy). You have a more modern CRT -- nice!
- Additionally there was a programming console with individual keys for the opcodes, and a (Nixie?) display. CHM has one in their collection (https://www.computerhistory.or…ections/catalog/102669971) but apparently not the rest of the machine.
- Memory was 4K core (persisted when power off).
- Storage was 2x cassette tape, and 2x 8" floppy disks. Mostly the disks were useful for program storage, and the tapes for data.
They seem to be very rare now, I hope you have success getting it operational!