I recently acquired, through no particular planning, two vintage divers in the classic ref. 2002 case. The wide variation in the dials didn't surprise me, but it was only when received them back at the same time from my watch guy that I began to notice the subtle differences in the cases. These both have the same movement (Valjoux 7730). Here are the differences I found so far:
1.) The Limit has knurled pushers (which I've never seen before) vs. smooth on the Le Jour
2.) The LeJour has beefier lugs that are tapered more extremely from bottom to top, and therefore have a wider bottom edge. The Limit, by comparison, has much more even lugs, and only a very small bevelling at the very bottom.
3.) The LeJour has a wider, aluminium bezel, the Limit a narrower, bakelite one.

The result is that even though the watches have the exact same dimensions (width, height, lugs), the Le Jour has more metal in it and is heavier, and just feels more like a tool watch on the wrist. I don't have a scale, but my guess is that it actually weighs more than my Nivada CSAD. The Limit is a bit more elegant and subtle. With the right strap, it could double as a dress (or, at least, dressier) chrono.

I really love these little variations, and, rather than feeling like I just own the same watch in two different dial configurations, it's nice to be reminded that the differences go well beyond that!