I have a old STR 643 from 1966, it has been sitting at the repairshop for 2 years now. After buying a donor pick-up we were able to fix it, only thing that still needs to happen is fixing the needle. It uses the B&O "all balance" tonearm. From research I find I need the B&O SP7 or SP14A MMC element, but it is possible that not only the needle is damaged but the whole element.  Now I think I can find the needle but the whole element is hard to get in my area. Now I was looking to maybe buy another donor pick-up, however I have a hard time finding what would be compatible for the parts I need. Also since some are very pricy. Anybody have any suggestion?