Your ’56 RD already has one wire going to one set of points and is connected to the vacuum operated cutout switch at the other end. This wire can be tapped into and the mag plate drilled for a second wire to connect to the other set of points. These two wires can then be hooked up to a kill switch or key switch to shut the motor down. I did this on my ’56 RDE and mounted the kill switch on the lower pan and it worked great.
Here’s a photo of your mag plate as it is now with the one wire and the next photo gives a reference where to drill it for a second wire.
