Finally I succeeded to grab a Junghans J80/3 (after 1962/63 called Junghans 680.72). This caliber was designed in 1940 but came on the market first in 1946. The special feature: The watch has a divided train bridge (ie a separate escape-wheel cock) and a sweep second.
Unfortunately, it is in poor condition and is incomplete. The second wheel is missing and thus also the second hand as well as the drive and the fixing thereof. The luminous material on digits of the dial is largely missing. The chrome-plating of the case is almost completely absent. Hopefully I succeeded over the years to complete the watch...
The caliber shows no shock protection, the diameter of the case (without crown) is 36 mm.
Here is a comparison with the caliber having the one-piece train bridge (also shown here: Junghans J80; Junghans 680.72; sweep second; far scroll down)