I just purchased a Beautiful Cab with a Singer 15 inside. AC100612. In wonderful condition, threaded it up and it started sewing right away with a primo stitch. The original book, Keys to cabinet, attachments all included for $50.00. Could not believe my luck. Don't know how to upload pics here. Does anyone have any good hints. I figured out that "Rhythym" is the key to steady sewing. I hadn't sewn on a treadle since is was 10 or 11 years old. I love it. Any tips or hints is appreciated.