Mitty,
The "shock from the machine" or "buzz" when you touch it is a sore subject on this forum. I've been chastised several times for my opinions and "suggestions". So I will tell you what I was told, and explain my thinking as best I can.
Older machines are polarized to a degree. Meaning that the original wires were wired with a hot and neutral side.
So were the switches, light bulbs, and sometimes motors.
The thing is, the components and wires aren't always marked like the modern ones are. The electrical industry didn't even start to use the polarized plugs until the 80s or the advent of electronics. Outlets have been polarized ( one wide one narrower slot) for many decades now. But even so houses made in the 50's rarely had polarized outlets.
Now, here is what I have read and have tried: If the wiring is in good condition, the motor and light fixtures too and you still get a buzz when you touch the machine, it probably isn't a bad wiring situation. Note the word "probably". Unplug the machine, rotate the plug 180° and plug it back in. The buzz will be gone. I have many machines with agood electrical system that will give a buzz unless they are plugged in the correct way. I've marked the old plugs so I do plug them in the right way and don't have a problem.
Now, if you get a buzz no matter which way you plug the thing in, then you've probably got a short inside somewhere.
Time to tear it down for a thorough exam.
Now #2, Switches are always wired in the hot side of the circuit. So if you take your older machine apart and disassemble the light, you can actually trace the hot side throughout the system and see how it's polarized.
I have rewired several machines doing this and found it to be true.
The cord block sets as used by the Japanese and other machines is also polarized even though the early ones do not have any markings or a wide slot in the motor / light outlets.
OK, I'm getting dizzy, I'll step off the ladder for now.
More than likely the wiring for your 60s machine is good. But check it out to be sure.
Joe