I remember those machines well. Back then we made practically all of our clothes, and bought lots of fabric. I remember seeing them at Beall's, J.B. White Company, J.C. Penney, Sears, and a great little shop in downtown Longview, Texas called "Famous Fabrics." I think they probably quit using them when the double knit fabrics became so popular because they couldn't be pulled through the machine. I do wonder why they didn't start using them again after the knit era was over.