After all my recent brake work and having thought I'd traced the problem to a leaking brake piston.
I was wrong !
A gentle trip to the shops ended up with my shoes covered in brake fluid ! Damn that will be the master cylinder then.
MOSS . . . . . . . . . parts ASAP ! Not going to re-build, far to many little bits to get in the wrong order or place or so it's going to be a new one. (MOSS don't even recommend rebuild kits.)
Stand by for next installation . . . . . . . . changing the master cylinder.