I know how you sector shaft looks . They use a used sector shaft and cut off one tooth from each end . the sector they use originally had five teeth and now has three. I used to use a new sector shaft made for 605 conversions not a used one and that makes all the difference in the word.
I agree with you about the safety of it . Binding and outright slop in the steering is not Safe.
I looked into their product for power steering and thought it was to expensive so I looked into making my own . This is how I got started . The box on my 58 is still my prototype box . I tested it for about a year before I even thought about trying to sell any . I am always looking for the perfect power steering for these old fords and I think I found it . I have my new prototype box ready to install on my 58 for testing . This box has NO WELDED PARTS and is a bolt on