Here's what I propose to fabricate as my front top wishbone.
I will be using 25mm x 2.5mm wall which will allow me to weld the threaded bushes into the tube as these are 20mm OD. The tubes are going to be bent at 45 degrees to give some extra weld/joint area to the main threaded adjuster.
I have moved the main threaded adjuster back 5mm to the book dimensions. With the Rose Joints I should be able to increase/decrease the caster as required for my car.
I believe DRCorsa has stated in Algas post on "self centering" that this will increase the caster by 1.4 degrees.
Camber will be adjustable in situ with a homemade camber adjuster.