There are four different sizes for TR sidescreen switches;
Push-pull, rheostat panel and starter(same size), light,and ignition.
I've been "mucking about" those switches for years & I've
never been able to source just the bezels. They were all
made by Lucas originally, but that part of the firm no longer exists.
There are aftermarket manufactures but you have to purchase the entire
switch to get the bezel and even then the bezel design is often different than the original.
I've looked into having them machined but the set-up costs are prohibitive.
Somewhere in the world there is a LBC pack-rat with a big box of nothing
but bezels but I haven't found him yet !!
Frank