Dave Brisco came up with a solution for the headlight wiring.
Dave's comments "I just saw the solution for headlamp wiring. Victoria British sells a headlight harness kit, part #10-679 for $29.95. Look under TR6. This is not a Lucas part, no need to refill the smoke reservoir Laughing The only draw on the original wiring will be to run the relays, less than 1 amp.
I had one in my hands today. Nice quality, at least 14 ga power wire. To install, you unplug both headlamps, plug the new harness into both lights, plug the original headlamp wiring into another plug on the new harness, ground 2 wires, run 2 more to the battery, mount the 2 relays, DONE.
You may have to remove the terminals from the plastic plugs to get them through the grommet on the headlight buckets, but that's all.
Easier and cheaper than making your own by the time you buy wires, plugs relays and terminals. It comes with a bright yellow cover sleeve over the harness, cut it off or leave it on, add half a roll of black electrical tape and it will look stock.
Red arrow plugs into stock headlight harness plug, blue arrow to headlight, the two red wires to the battery, and there is a ground for each headlamp."