My guess is headset is SAIKO (polish company, run by Janusz Kowalski, former world champion). or some campagnolo copy. There were many workshops which used to make gear like derailleurs, seatposts, stems, headsets, cranks, hubs, headsets based on italian components.
big thanks for the hint, might be the correct direction of search.
big thanks for the hint, might be the correct direction of search.