Ignition switch removal for '56 XK140 doc

My ignition switch on my 140 seems to be worn or faulty. Car just stopped the other day while still in my shop. Wiggled the wires and it worked again then quit several more times. How do I remove the switch? My Mk2 brake warning light and toggles have the notches to use the tool to remove them. My ignition switch has a smooth circular bezel. How can I turn it to get the switch out if needed without harming the veneer? Have what Moss says is the correct replacement but it has a heavy looking hex nut to fit. Not pretty and just seems to be incorrect. Thanks.

You have to pull the instrument panel to get to the backside.

I can get to the switch after removing the drawer. The Moss switch I have is much too long. It will not fit on the mounts that the current switch is on. Going to check with SNG Barrett Monday. May try Welsh as well.