It didn't take long for the cardboard holding the switches in place to wear out; in fact, it never held them securely at all, so I decided, as probably another temporary measure, to make a plastic piece. This is cut from a BeebMaster Econet Clock veroboard box. I don't have a drill, so I made the two holes using my electric screwdriver with a sharp wood screw to pierce the plastic and start the hole, and then I used a big nasty screw to widen the hole, and finally I had to use the screwdriver bit iself to work it wider.