Chris, with the draglink unhooked, turn your wheel lock to lock, if when it crosses center you don't feel a tight spot, you need to adjust the steering sector so it goes deeper into the box. If that doesn't work, the worm gear or sector gear is worn out. I had an original '37 box well worn with the same play you have. A replacement sector gear fixed it.
$1700 is a lot for a gear box rebuild or replacement, I would for sure tear the original apart for an inspection first.
