This is a Singer 221 Featherweight sewing machine that belonged to my Grandma. It was made sometime around September 1947.
The original motor was this "Catalog 3-100," rated for 100–110 volts. I ended up swapping it out for a new Alphasew motor.
The Featherweight motors that have lubrication holes should be greased with petroleum jelly (Vaseline), not oil or any other kind of grease. For $2.59 I bought enough to last several lifetimes. Here I've loaded it into a syringe for easy application: