Sorry about the repeat post. I was getting an error pop up, now I cant figure out how to delete the duplicates.
No worries, I'll delete the duplicates for you. I believe you can do that by clicking on the edit button on the lower right. Should work for your posts but not other members. Moderators have that ability on all posts.
[on edit] I believe that an AD steering box could be rebuilt in-frame, but the rub might be taking the steering shaft out the bottom (something is guaranteed to be in the way with the box bolted to the frame. Not sure if that would apply to a '58. But if you could do it in-frame, it would likely be MUCH harder than just removing the assembly.