Cams are relatively easy, since it takes black top hat cams. It's mostly a question of what you are willing to pay for them. I think there's two type black top hat cams, and it's the version with two holes sort of placed at a 90 degree angle.
You will find the replacement screw by searching ebay now and then, and those who care for vintage machines. The trouble is to identify the correct type, but it's within doable.
For the motor I don't know, it can be damaged, but more often it's something that needs sorting out with the pedal, adjusting, a capacitor there or in connection with the motor. I'm not quite sure where the capacitor turns up on the 401s. It could be anything electrical, a loose wire,...