You've got a mixture of Singer, Greist, and Kenmore accessories as well as Singer and I think Kenmore cams.
Even if the machine don't run, you got your moneys worth in the accessories and cams.
Before you condemn the motor, check that the machine turns freely. 401s are not hard to turn normally. After eleminating that, check the wiring at the motor, and at the plug at the base of the machine. Also check the cord to the wall socket and to the knee controller.
Lots of things to check out.
Joe