I have a Pfaff 7550 and just love it. It's been a good machine every since I bought it 20 years ago. The only thing I could say is that I don't believe that Pfaff is making replacement parts for it any more since it's so old. My dealer tried to get tension discs for my machine and we couldn't find them anywhere. Pfaff didn't even have any. I would find out what the warranty covers, but if it is rebuilt, I would go for it.
Bonnie K