Hex Screw set switch cluster CNW Master Cylinder Norton Commando stainless
If you have this type of Master cylinder, I have found that this type of screw is easier or possible to install the switch plate. (If you use the allen you will need to modify a ball end allen wrench and I think it is still impossible on the top right near the reservoir).
This set looks good stainless steel and you can use a 5/16" open end SAE wrench
Kit does not come with the wrench