The book shows a shaft with top & bottom uj `s to fit escort column & rack to be modified to suit, what does it come from and whre can I get one

Assuming you are using a sierra column, I used the lower column from a power steering sierra which is 19mm round tube, but the lower joint is too big for an escort rack. So I drilled out the rivets on the donut and attached the lower clamp from a manual steering sierra and replaced the rivets with M8 HT setscrews.

If you are not using a sierra column, I'll pass, and someone else will help you

proper metal u/j,s are from an allegro,people like raldes do after market ones tho