Damaged housing or shaft allowing Fluid past?
I looked at the flange and thought it could be smoother. A neighbour has a lathe so took it round and polished with wet & dry with some oil. Definitely smoother now.
On refitting made up a wire spacer the thickness of the lip and then fitted to the flange (with washer and nut) and screwed the new seal into place. Hopefully that will make sure it went in straight with no damage. Undid nut, took out flange, got rid of spacer and then reassembled the flange adding the rubber and metal washer.
Hopefully the polishing and new method of fitting the seal will work. Otherwise it will be a complete flange kit.