Vintage BMW Motorcycle Owners

There doesn't seem to be much information on this sidecar that I have found.
Was it offered to the public or was the demand so low it was built by request ?
What I can see in pictures, the frame resembles a TR 500 on the right front.
There are some photos of a Zundapp/Steib restoration at a museum in Germany,
one shot of the old car that was used to pattern a new body ,but no frame shots.
Any information out there?

Can you post a few photos?

Do a search for ''A green elephant at the museum for industrial culture '' should get you some pictures.