I trashed a cabinet like that one that was beyond saving. The controller was built in to operate with a knee lever. Unlike other machines of that era, it was not removable. The controller part was buried in the bowels of the cabinet. You had to destroy the cabinet to get to it. I still have the parts of the controller (no idea why I haven't trashed it). I'm just saying this, in case your cabinet is like the one I had.
bkay