i have a 301 and a 503. I use Schmetz or Organ needles in both and have for years with no problems. Some Singer enthusiasts tell you otherwise but that has definitely not been my experience and IMO is outdated information. There are after market feet that fit the Singers. They are not as good as original but will in no way harm you machine when you use them. In general, I find the vintage machines to be very "unpicky" about thread and needles. I've used all sorts on mine and never had a problem. I've also bought after market bobbins and had no problems with them.