Austria Blacked-Out Eagle

I have this stamp from Austria, Scott 244, that has every word, number and ornament blacked out, with the exception of the denomination Kronen. Even the white bar of the Austrian flag has been black out on the coat of arms. This is part of the last issue before the Republic of German Austria became the First Austrian Republic in 1920. Why is it all blacked out? Is it the Germans denouncing the new government or something else?

I've not seen this before. Doesn't look like an overprint, nor does it looked "blacked out" to me. Looks more like someone did some doodling and colored in some of the ornaments. Just my non-expert guess.

If I had to guess I would say someone simply tracing.

If it is someone tracing, why leave the word Kronen and the ornaments in the upper left and right corners exposed.