There were eleven wires to the l/h handlebar switches - 5 for the dip, 5 for the turn signal switch and one for the horn.
One, the brown/white to the signals, was accidentally pulled off during dismantling, and as that's the power supply it had to be soldered back on.
After careful consideration (as if) I removed two wires from the dip switch - I
hope they were for the light checker and reserve lighting unit, both of which have gone to the Yamaha parts bin in the sky. Ditto two wires removed from the turn signals, which were
probably to do with the auto-cancel function, also binned.
After cleaning and reassembly ( with grease as recommended by 5T), which was not as fiddly as I had been dreading, was able to feed the seven remaining wires through a length of heat shrink:
View attachment 159066
View attachment 159067
View attachment 159068
I won't apply heat to shrink the sleeve until it's back on the bike, in case it makes the whole cable too stiff to route.
Toyed with the idea of drilling the handlebar and routing the wires along inside. I did that on a Kawasaki Z1, the famous Hiro Hito, and was gratified how the handlebar area looked much tidier. But decided not for now. Let's see if it all works first . . . and then maybe.