copied the pictures and enlarged them- and it does sort of look like the plug might be modled into the machine - at least part of it. There are two screws on the face of the plug so half of it does come off the machine. I can see the wire running under the arm from the motor to the light, so the wire does not run inside the machine like I was guessing it might.
I did find a picture of the original light - I think this machine might be a lot more work to restore than I was thinking - but a challenge is always fun. It does appear that is an original case for the National.
Did a bit more searching and found a picture that lead back to this sight - CarolineS has a Damascus that is basically the same electrical as this machine - I'll see if I can get a picture of the back side of it. The good part, it may not be that hard to find a Damascus to get the motor and light off of.
Oh well, I'd better stop, I don't even have the machine yet and that might not work out LOL!!