Singer featherweight serial number dating
The Singer 99k sewing machine is small in size measuring only 12-1/2" wide, this image shows an early version the 99K (99K21 - 26) made between 1924 to 1954. The stitch length was adjusted via a screw and the machine did not stitch backwards.
Later versions 99K31 had a stitch length up-down lever with reverse stitch and numbered tension dial - Year 1955 The Singer 15K is always recognised by its tension unit being on the left face of the machine.
The Aluminium body machines were made in Black/Gold, Beige or Beige/Brown.The machine in the image had a small type stitch length, later varieties had the stitch length lever protruding out from a large round numbered disc.The Singer 15K was manufactured over many years from 1910 - 1964, then reproduced again in 1982 called the Singer 15N.The difference was the 128K was smaller at only 12-1/2" bed size.
It always look a neater machine because of its compact size.
Its manufacturing year was 1955 to 1964 The Singer 66K is the large version of the Singer 99K.