All of the control arms serviced by Ford should have had at least some assembly grease in them, which would protect the ball/bearing surfaces. Of course, as mentioned, depending how they were stored over the years, moisture could have worked it's way inside and caused some corrosion. Other than taking the rivets out and inspecting everything, I don't think you'd really know for sure. If the arms look good and are not rusty, I would say it would be fine to use them.
Now, concerning NOS control arms, there were a few styles that were serviced. They may or may not be exactly like the original factory parts, just as an FYI. There are ball joint design differences as well as a couple other details.