Front indicators retain the headlights
These little tabs are cut from 3 mm thick sheet. They have 3/8" UNF nuts welded to them to suit the indicator stalks:
They weld to the rear mudguard stays:
For wiring up, I am using these 'Japanese Bullets' - small crimp on connectors, fully weather proof.
Put a dedicated earth wire into the shell and attach it to the bulb holder with a ring terminal. By design, the earth path on these repro indicators goes through the plating... Nasty...
So, what you can do is bring an earth wire down the indicator stem to a dedicated earth wire. The earth wire can connect to one of the bulb holder mounting screws. Normally I don't use these modern terminals, but no-one will ever see this:
The handlebar switch is available as a generic indicator switch from many Brit bike outlets. It has three wires: a common yellow wire from the flasher unit, and red and green wires for right & left:
All the wires come into the headlamp where the red & green wires are terminated with a Y connector: one path to the front indicator, the other into the loom heading to the rear. The yellow wire connects to the flasher, which sits in the headlamp shell, protected by a rubber sleeve - MZ style!
The flasher is supplied from a dedicated fuse