Just a quickie, what thread is the transit ball joint (joint end nyloc) ?

Cheers.

Depends on ball joint brand

iirc my bottom ball joints were M14 x 1 from memory. I got some spare nylocs from a local motor factors / engineering spares place. I had to take the ball joint to them and they matched up the nuts. Loaned original nuts to my dad before i realised they werent so easy to get hold of.