Yes,
I had a go at this myself.
I've uploaded a small diagram of how easy it is to accomplish.
As long as Commodore used the same colour scheme with all their a500's then the colour of each wire correspond and are are shown in the diagram. Connect an a500 keyboard controller daughter circuit board to the keyboard MPU on an a1200 and it supports all the keypresses' available....
Hope it helps with your project.
