Hi and Welcome to the board.
While I am an avid Pffaf user - I can not help. However, if you do not find info here and you are on Facebook - there are several Pffaf user groups there. One that might be of interest for you is for "Vintage Pfaff" (which I am not a member but may be a great source of info for you) and another "PFAFF MACHINE OWNERS GROUP" (all caps) and this one I am a member of and there are several techs that usually post in depth responses to folks with problems.
Good luck with it - if you can get it going you will love it!!