At a point in time I had accumulated about five or six steering boxes thinking I could mix them up resulting in two or three good ones. I was wrong.
I don’t recall that the worms and sectors had any part numbers on them. I went through a lengthy exercise of matching things in different pairs, discovering that there was only a one-to-one relationship.
Furthermore, most if not all of the wear tends to be on the sector.
In the end, I decided just buying new matched sets from Argentina was the best solution.
I can imagine a past when a fabricator would tool up there machinery and make matched sets. They would conform to the performance specs regarding engagement and ratio, but might have slightly different arcs, meaning each production run might be swappable, but not with a different batch.
I dunno. But, a single worm gear is probably the one remaining unicorn looking for a mate.