Unfortunately I don't have a good enough picture but it is identical to this one:

Credit Chrono24
You can see that the long hand with red arrow is the chronograph minute counter, the long seconds' hand is the chronograph seconds counter while at 9 it is a 24 hours counter and at 3 a small second. Looking at the layout of yours I would tend to think it is a more recent version (? but you seem to know a lot), as the layout is more "logical" than mine.