Grundig Satellit 600 Professional - Volume Control problem and Auxiliary Tuning Scale Drive belt broken

I am assistance or to source a English service manual for the Satellit 600 order to see how to open the casing in order to get the Volume Control in the front face, and how to fit the replacement belt for the Auxiliary Drive

I have searched the manual list but cannot find and English version of the SM, and have added this request in the Wanted section on the RHS of page