You know, I wanted to collect all of those cams at one time and I do have 0 - 23 and 51 - 59 but then I realized I don't really use them... My 411G which is the only Slant-O-Matic I kept has all of them built in, I actually use my Pfaff for most mending and utility stitching and I don't do decorative stitching... still, like my Singer Sewing Reference Library, it's nice to have them in case I do decide to use them.