There was a post not long ago about someone from MI (Saginaw) where these were made that is also doing good repair. You can search the posts with the search feature.
I think that's in the end cover, so it just might be simple top end fix, if the other parts aren't worn. There might be a lock nut under that has to be loosen/tightened, so maybe not tight.
If it's very old, the seals will probably start to leak as the "slop" wears them. The needle bearings(Torrington) will go too causing slop. Good bearings = good sealing, bad bearings = bad sealing. Otherwise, pretty bullet proof compared to modern junk.
I do my own, and some times not very effectively. These are much more mechanically complicated than the later tank style and parts harder to obtain. I wouldn't worry about a few bucks when it comes to steering safety. Also, what their warranty and return policy is.
One of the things that comes with experience, if it isn't broke don't fix it. Lots of the undisturbed crud and sludge prevents leaks. But when not functioning it's time to intervene. We had a acronym in safety, TAKE, and the "K" was for knowledge. Get the proper info/diagrams/instructions on your unit before attempting repairs/adjustments. Prevents incidents like this.
