Singer dating machine
You have indicated that the Tension Adjustment Knob is on the Left Side of the Head pointing LEFT.
You most likely have a Model 15 Series machine but there are several styles which we now have to determine.
If the Sewing Bed is 10 to 12 inches (25 cm to 30 cm) it is a Half-Size., you have a Singer Model 221 or one of its variations such as a 221K or the Model 221-1 or one of the colored versions like the 221J which is a tan colored model.
Look at the pictures below to confirm your machine's identity. You have selected the Faceplate that is Smoothly Rounded and Rectangular. It should be encased in a squarish type of housing.
Now open the slide plate and look at the Bobbin Case.
If you’ve nabbed one of these beautiful bargains at a local market, auction or car boot sale, it’s worth identifying the age and model of your machine to see if you’ve managed to pick up a rare antique.
Does your machine have a small chrome colored wheel on the very front-right corner of the base? Without this little wheel the thread path is across the face of the machine from upper-left to upper-right making this an early Model 15 machine.
Very popular with this style of machine was the "Egyptian" style decals. With this little wheel in the right corner of the base the thread path is diagonally across the front of the machine from upper-left to lower-right to the little chrome wheel and then vertically up to the bobbin winder making this a later Model 15 machine.
Check to see what drives the machine as it may be Belt-Driven or Gear-Driven.
Is there a RUBBER BELT that connects the motor to the Hand-Wheel?