The Norton Commando Gold Portfolio (page 88) lists 26 changes between the 750 and "the new big Norton" 850 includes item 5: "The latest Lucas switches are fitted, incorporating longer flashing and dipper controls. The push-button extend more prominently. A red kill button is fitted."
On review, The Norton Commando 850 Interstate - Road Test (Cycle Australia) review of April '73 says the following: "The Lucas "space age" switches are supposed to have been improved. Actually, all that has happened is that the blinker and light switches have been lengthened. It hasn't made them any better. On the right-hand bar are a kill switch button (only kills the motor while your thumb is on it), a nothing button, and the indicators (as mistake, this, it makes throttle operation coming into crossroads very difficult). On the left-hand bar are the headlight switch, horn, and headlight flasher buttons. Only the latter two are satisfactory. If we bought a Norton we'd be tempted to replace the lot."
Ouch. The pair of switches I have from an April 1974 include on the right side a red kill button, black button, and double-thrown paddle in black. On the left, a single-throw black paddle with two black buttons.