That orange screw is for locking the adjustment against movement after sighting in.
I just sent an email to waffenbultmann@gmx.de . Maybe someone remembers after half a century or several generations where the company once sourced their scopes. At the time this scope was made there were dozens of small optics makers in Germany, Schmidt & Bender just one of a lot. During the 1970s most of them succumbed to the competition of cheaper made in Japan scopes.