Since I wanted to keep the original looks of the scooter handlebar as clean as possible and I’d like the rear brake light to engage when braking with the front brake, I’ve opted for the old PX style switch.
The way to go is to cut the brake outer and stick this plastic thing in between. Connect the cables as you would on the foot brake switch and just thread a control cable through.
In the last delivery I had received a hydraulic hose with the wrong angle on the banjos. After returning it I received a replacement with straight angled banjos.
I connected it up to see if the length of the cable and the angle of the banjos would work. Will have to correct the alignment and angle since it touches the dust cap right now. I may say that the setup looks solid and will probably work. 
I do get a good clearance from the tyre and that’s most important. I wouldn’t want them to touch.
It will be interesting is to see how the Scootrs slave cylinder works. It is held in place by the original circlip.
Lambretta TV175 Series 3 