Many Thanks Laitch for the wiring diagram. The install worked!!! And, as you said; So easy.
I had originally tried to install the m-lock near the relay box under the seat and had evidently chosen the wrong feed wire from the electrics.
But; installing it in the position of the original ignition key I had the correct wires to connect to.
One more question: the m-lock on my 1991 K75S is working without the motogadget capacitor that I thought I might need. The K75S of mine starts first time every time and doesn’t appear to draw down the battery much in doing so, which might otherwise cause the m-lock to "drop-out".
So; Can anybody comment on whether the motogadget capacitor is needed or not on the K75S?