Bought this old function Generator from eBay for 40€ Delivered(!). It works without any problems. Now comes the good part: The insides.
Photos of the main PCB is attached. The best thing about the PCB is that the "functional blocks" are labeled on the silkscreen! The seller even provided me with schematics, a (hand drawn!) block diagram and a PCB layout of the mainboard. Photos of everything i mentioned are attached. I don´t know from when this is so maybe you know some more.
Link to more pictures because I could not upload them all here:
https://workupload.com/archive/stNTPrw