Hi Alex - I remember watching a motor refit & full square up on the PKF by a colleague over 20 years ago, but can't really remember the specifics - I just remember that it was a real pissy job that involved a lot of swearing in German and getting inside the machine.
Try contacting Metabo Uk in Southampton - Metabo bought Electra Beckum & you may get lucky and be able to speak to any of the original engineers if they are still there..
Just FYI thread below which you may have probably seen already? - side panels I now remember & also tilting the whole saw on it's side helps - blimey it's all coming back to me now. elektra-bekum-pkf-255-v8-clean-out-t3392.html
All the best,
Cheers, Nick