In this watch, the gear train bridge shows a variation. There is a receptacle for an additional spring, presumably to better perform the second wheel. The second wheel is missing and thus also the second hand.
Here is the movement with a singular train bridge: Junghans J80; Junghans 680.72; Zentralsekunde
Again, I find it difficult in some caliber allocation. With the above list I tried to provide some clarity on the different caliber and their designations.
The movements were produced at the same time with or without divided wheel bridge. There are versions with 7, 11, 13, 15, 16 and 17 jewels.
There's caliber Junghans J80 with various imprints on the bridge: J80S; J80M (was probably Meister).