Vintage 1940’s ATOMAT German Radiation Tester Geiger w Leather Case World War 2

Description

Vintage 1940’s ATOMAT German Radiation Tester Geiger w Leather Case World War 2.
Very scarce item with not much written history to find. ATOMAT which is known for its fins clocks may have been commissioned to manufacture this item as a part of the war effort. This is a working theory and I could not find anything to support it, mind you. If you know more about this item, I would love to know the history.
Please note that the original glass seems to be intact but has worked its way loose. Also, the sewing at sides of case have come undone and both sides are hanging by a few threads. Really wonderful piece to look at mechanically and to marvel at what tales it could tell.
Please feel free to ask any questions and I will give the best answer I can find. The item measures 7 by 4 inches when buttoned up in case and weighs roughly 2.5 pounds