Glad to report that this ended up being an easy fix.
Looked at the upper arm that I hadn’t fitted and noticed that the underside of the arm was not smooth with marks looking like somebody had tried to lever the arm down to enable the ball joint nut to be undone.
Quick go over with the flap disk to smooth it out, assembled and plenty of clearance. Same on the side I had already fitted.
As for the castle nut realised that I had used the shorter ones from the track from ends, used the right ones and it all looks good.
Phew. Thought I had made a mistake in my component choice.
Onwards!!!!!
P.
