Don't think "repro" was inferred, rather "replacement" parts.
The ball joint looks original to me, but with it being bolted on, it doesn't follow the normal pattern of riveted joints.
With a car like a CJ, lots of stuff can get tweaked that normally wouldn't happen on something like a standard 289 or I6. Really no telling what the story is. If you have the original upper control arms, maybe there are marks around where the rivets would have been?