You need to look at the bottom of the bobbin to make sure you buy the correct replacement. I believe the 758 has a small slot like a minus sign. I also have a 1050 which uses a similar bobbin but it has a slot resembling a plus sign on the bottom. Make sure that this slot lines up with the little gear that slides up in this slot when you engage the bobbin for winding (push over the little bullseye). My 1050 has gotten touchy and I have to be very precise in the bobbin placement before engagement for winding.