On the 1956 & 57 steering box, there is a seal integrated with the flange for the shaft coming from the steering wheel. Usually, this seal never go bad; it prevents water to come into the steering box.
On the '58 steering box, this good seal was replaced with a dust cap pushed on the end cover; it is no more intagrated with the flange. With the time, the rubber lip get brittle and deteriorate, allowing water to come into the needle bearing.
I never found a change of part number in the bulletins nor in the parts book. Having no reference, I could not search for a replacement dust cap.
Recently, I had a second steering box coming to my "shop" because it was leaking. Of course, the rubber lip of the dust cap was gone. What to do?
I found that the seal CR8772 had the right inside and outside diameters, but how to install it?
I removed the flange, did a 2 mm spacer which was soft soldered on the dust seal core and attached the reworked seal with 2 small screws on the dust seal core and spacer assembly.
If someone has a better solution, the right part for example, I'm all ears...