Can anybody identify this rare button for me?

[dwg]

There is a black felt like material surrounding the eagle.
Button is unmarked

[Jeff Clark]

These buttons were supposedly taken off a tunic in Wilhelm Grimm’s house at the end of the war along with his Iron Cross and a few other things (which I don’t recall).
The stuff was together for a long time, and then got split up over the years.
I got the Iron Cross and my 2 buttons from Wolfe.