Ferret erratic knocking from left hand side front.

[motto (RIP)]

Having little experience with tracta joints I may be speaking out of turn but in general terms the importance of lubrication cannot be overstated. The joint in question appears to have been operated bone dry and simply filling the housing to the correct level with the correct oil may have solved the problem despite the appearance of the parts. I would have no hesitation in following Richard's earlier suggestion to remove the high spots and put it back to work. (Though he hadn't seen the damage at that point).
After all, any of the other joints in the vehicle could be almost as bad and you wouldn't know until it started talking to you.

David