I agree with Cathy and Joe. My grandmother's Singer 403 came to me set up with the extra cord wound around a hook. But, the machine also came with another foot control. Grandmother sewed a LOT so she might have bought a second foot control. Why I cannot fathom. I know you can use either/or on the machine but I need to look again and figure out whether you can plug both of the controls in so either one can function.
The above is about as clear as mud. What I mean is can both controls be functional on the machine at the same time without doing all the reconfiguring business to switch from foot pedal that runs the knee control to foot pedal that sits on the floor and is operated with the foot? There, that is a little better.
Just curious.
Pat