Sewing Machine under base linkage Montgomery Wards badged National sewing machine vibrating shuttle. 1) Vibrating shuttle carrier on bar with pivot screw. 2) Feed dog bar with feed dog attachment bar. Solid brass parts.
Works on some National Sewing Machine Co vibrating shuttle machines. (Homestead, Damascus, New Home, etc. but especially Damascus VS). If your undercarriage looks like scan #2 , bet it will work.