You'll see the Nazi eagle impressed in ammo from Germany and Austria during this period.
Mostly I've seen it in rifle ammo, 8x56R Stery ammo.
I agree with you that the ammo was destined for the Austrian MP34 submachine gun.
The fact that it is in clips is logical, because what a lot of people don't know is that the magazine housing on these guns doubled as a magazine loader for use with the stripper clips.
Many years ago I worked for the Pennsylvania State Museum, and one of the guns in the collection was an absolutely gorgeous MP34 that had been captured by the 28th Division in World War II.
It didn't look as if it had ever been issued or used.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.