I have a Bernina 730 Record -which incidentally I am planning to give to my mum for Christmas since she fell in love with it when she tried it this summer when visiting me. Mine dates from the early 70s and as far as I have noticed, the only plastig gear is the infamous cam stack gear. I got my machine very dirty, almost caked up in old oil (including the motor which I had to degrease to remove the odious smell when the machine was running) but the gear is still intact.
I agree with Mickey; the paint is delicate especially around the free arm, where you slide the extension bed. If you're not fastidious about perfect looks...
Once nice piece of trivia I just found on a French sewing forum: the 530 in 1954 was worth 800Francs that is the equivalent of a month and a half salary of a skilled factory worker.
