Extender / LED insert for quiz game button box

Buttons for television quiz games, if not directly mounted into the podium top, generally need an enclosure of some sort. A problem arises in that suitable size boxes are not deep enough to accommodate the switch and connection terminals.
This "box extender" is designed for a commonly-available Series 30 enclosure, and adds about 30mm to the depth of the box. If printed from suitable translucent material, it also allows for an LED strip to be placed in the slot provided, and these are intended