So the electrics arrived and I didn't bother taking pictures of the install, but once it's sorted out I'll reverse engineer(?) it with some pictures etc. Also the lights aren't working yet. But was it worth it? In a word, yes. So excited as I that this was composed on my phone while up the bush, and I'll leave it verbatim:
"..i write to you from Knocklofty.
drag
brake is awesome. in gravel it will retard the rear just enough to
make it loose and happy to fishtail for the Scandinavian flick :)