This is a nice original low shank straight stitch foot and thumb screw. It is part # 45321 and will fit Singer models 15, 27, 28, 66, 99, 101, 185, 192, 201, 206, 221, 222, 306, and 319. This product is available from Central Michigan Sewing Supplies.
Presser bar – Vintage Sewing Machines
DOMESTIC STRAIGHT STITCH LOW SHANK SCREW ON FOOT FIT SINGER
Restoration of a 1975/76 Vintage Kenmore Model 158.1941 Sewing
Vintage Original Singer Low Shank Feet & Attachments – Central Michigan Sewing Supplies Inc.
Singer Model 66 Sewing Machine Parts: Original and Replacement – Page 7 – Central Michigan Sewing Supplies Inc.
Straight Stitch Hinged Foot and or Thumb Screw Sewing Machine
Vintage Original Singer Low Shank Feet & Attachments – Central Michigan Sewing Supplies Inc.
Singer Model 223 Parts – Page 4 – Central Michigan Sewing Supplies Inc.
Singer Model 66 Sewing Machine Parts: Original and Replacement – Page 7 – Central Michigan Sewing Supplies Inc.