Infanterie Sturmabzeichen Authentication

[Laconic]

Hello, I've cropped my pictures to show only the item iself.
I've recently been offered this Infanterie Sturmabzeichen, however, I've been more of an EK collector in the past, so I am somewhat hesitant on my own judgement despite looking up online. Evidently, it's an unmarked one, and the pin doesn't seem to have been fixed before.
Anyway, I would be deeply grateful whether anyone here could provide some insight.
Thanks!

[rbminis]

Originally referred to as a "deformed leaf, vertical crimp", these have now been attributed to the firm of Wilhelm Deumer.
Here is mine to compare.
Ralph.