There's a build log from many years ago, I will try and link it...
http://www.mycncuk.com/threads/651-W...ht=Warco+Major
I fitted zero backlash double nuts, big disappointment, so I sprung them and it was like magic.
The springs mean that I have no backlash up to 1/4 ton but if I ever pass that loading presumably everything will go horribly wrong.
I do get some sideways slop in the quill if I forget to pack it out with thick, icky grease. Open to suggestions.