Identify electronics ON/OFF Switch by way of specialized keyway cutout

Can anyone identify manufacturer and part number of the ON/OFF switch that fits the keyway in top right section of this picture? The switch requires a key. I need dimensions for this cutout and deliverables for this project should include the engineering models/specs provided by maker of the keyed-switch for applying it into designs. Dimensions: outer ring diameter is 1.265 inch and inner circle diameter is .430 inch. Limited more dimensions available to anyone taking this on for confirming or narrowing down. The switch is part of a busbar system distributing 480V power in industrial settings.

If your field is electrical engineering and design of electronic systems, this might be an easy task.