Strange wiring at the rear? Or is it normal?

[dcurzon]

i came up with the same assumption, but seeing as i'm finding all manner of oddities on this bike*, thought i'd ask those in the know

*the previous owner (and only owner) told me about the one headlamp for dip, one for beam, no modifications done to the bike.  I got home and wired up the right headlamp and found there was some wiring already running to it, from the battery +, with a blown fuse... anyhow, disconnected that lot and went with my own version instead.  Also, the thinner sprocket nut is fitted, so have now got the thicker one ready to fit when i do the chain