Ignition Switch With Keys For 1971 Tr6r?

The ignition switch for my newly acquired 1971 Triumph Tiger TR6R is in sad shape and difficult to turn and the key is about to break off. It will only switch to three positions.
I have searched a number of suppliers for a replacement for the switch with keys and find NOS Lucas switches for the years before and after 1971 but not for that year (or 1972). According to the Owner's Manual it should be a four position keyed switch. Does anyone know where I might find a replacement?

 

EFT,
Thanks. I find their website confusing, but at my age I am easily confused! I just ordered the switch.
Jim