Your mixer is a really rare device! There is one in the "Deutsches Kunststoffmuseum".
https://www.deutsches-kunststoff-museum.de/sammlung/virtuelles-museum/k-2009-00257/
Perhaps they can help you.
One piece is a "Breitbandentstörer", (broadband surpressor linefilter, often brandet ERO) containing capacitors. It is similar to this one: (use Google translate):
https://www.hobbyschneiderin24.net/forums/topic/179232-pfaff-230-motor-breitbandentst%C3%B6rer/