Mystery Black Wire (Now With Pics Loaded)

Trying to get the wiring back together on my 76 KZ750 Twin. You know the bundle of wires that comes from the left handlebar controls? (horn. signal light switch and hi-beam switch)

Here is the wiring diagram:






And here is my scooter












And here are my puzzles;

1. I've got a black wire with a female blade connector coming from the handlebar and no corresponding wire on the main harness to connect it to. What is this black wire supposed to connect to? To make matters worse I have no male blade connector of any colour to attach it to anywhere in the vicinity

2. The wiring diagram shows a black wire with a connector going from the horn to the horn switch but mine has no such connector, just a black and brown wire that plugs into the horn.

3. Just above the horn on the diagram there is a brown (looks more red than brown in the diagram but its brown) wire little stub going off to the left and terminating in the middle of nowhere. I don't see this anywhere on my bike.

The 6 pin connector checks out perfectly against the diagram and the blue wire with a bullet connector also checks out fine.

Any help would be greatly appreciated.

EDITED Pics didnt load

The black wire grounds the horn with the button. The brown wire is power.
Steve