Ok. The part came and I gave myself plenty of room to work. The right sized spanner on and Lucy lefty, righty tighty constantly checking I’m going to undo not tighten.
Spanner on, push away and the bloody thing just snaps off. Apparently I tightened the last one too much.
So drilled out, re threaded and the new fitting sort of screwed/forced in by a local garage. He would not take payment, a drink unless it works leak free.
I will refit later but I have my doubts.
Tony