None of the vintage machines have stitch regulation. Are you talking about a hopping or darning foot for free motion quilting? Yes, the 403 has a slant, darning foot available. But, I agree with you that they're not good for free motion. If you search through the vintage section, you'll see many people rely on their 301's for FMQing. I have many vintage machines that FMQ well. The 301 is one of them, but I have many others that do a fine job. The 400 and 500 series Singers are kind of unusual in that respect only because of their design.