Got some electrical gremlins, brake test switch doesn't work and headlamps / flasher stalk are doing weird things :-/
Firstly, I found the following multiplug under the dash, looks like it should go to a switch?

This is the back of the brake test switch

And to top it all off I found a brown wire which has melted/burnt out in the engine bay wiring loom, traced it to behind the washer bottle and not found good wire yet and the other way traced it to behind the brake master cylinder and again haven't found good cooper yet, never replaced wires before, not looking forward to this!