When I renovated my BT7 about 15 years ago I did the steering box myself, including fitting oversize needles in the peg and a new reamed bush on the vertical shaft. Although the car was fine to drive and it got through the local tests, there was still around 2 inches of free movement at the steering wheel perimeter. The problem is that the scroll wears in the straight ahead position, so although it can be adjusted out, it then binds in the non straight ahead position. Also the vertical shaft wears oval so that a new bush has little effect.
Finally decided to give the car a treat and have just fitted a new box from SC parts. There is now no play in the steering which is great but obviously it will never compare with a modern rack and pinion system. Just slightly less arm waving to be done /bcforum/images/%%GRAEMLIN_URL%%/smile.gif
Richard