How can I replace cords on old sewing machine?

I have a vintage National/Eldredge model R40 rotary sewing machine probably from the 40's or 50's. The electrical cords connecting the knee controller to the motor and the motor to the wall outlet are disintigrating. The machine still runs, but I am nervous with so much exposed wire.

How do I replace these cords, and any ideas where I might find parts?

Thank you.