A very nice attributed Wilhelm Deumer example.
Judging by the amount of this model still in existence today, whom-ever produced this example had a large production order.
As my good friend Stewy states, there are multiple variations of the hollow tombak attributed Deumer. Yours is what I refer to as the Type or Die 2 variant.
The reason it's the Die 2 example is this obverse pattern was also used to produce the zinc hollow version of this same design, the Die 1 is not.
Congrats on adding this quality tombak example to your collection.
Best Regards, fischer