Probably the Caliber Junghans J58 and the Caliber J59 are no In-house caliber. They were pretty sure made by Felsa S.A., Grenchen, Switzerland.
The caliber Junghans J59 exists in two versions, with separate escapement wheel (earlier movement; shown above) and (shown below) without.
Here is an example of the implementation of non-separate escapement wheel with 15 stones and with gilded movement.
For a long time the Junghans J59 held as first by Junghans self-developed in-house caliber. But the caliber Junghans J53 (13```) which was developed in the Junghans factory Schwenningen under the name NOBRK was the first watch that was developed and produced of Junghans in-house.
1931/32 the Junghans J59 was replaced by the caliber Junghans J80.