The mating connector (picture attached) has blue wire on round side of connector and grey/blue on square side.
I attached pic of inside of service manual also as requested. Many thanks for helping. I really appreciate it.
During this refurb I have also to replace the rear brake callipers, and hoses. Where the solid brake line joins to the top of the flexi hose I think the union will crumble away when I try to unscrew it - it is badly corroded, so my plan would be to cut the solid brake line directly above the union and put a new union and flare the end whilst in situ. Wondering - is the solid brake line on these steel? It's hard to tell as painted black. Also I am guessing an M10 x 1mm union is required for this? Finally, what specific flare is needed? A bubble flare perhaps?