Need help identifying WWII era PP / PPK Holster

Hello and thanks in advance for some experience advice on what exactly this holster is. My guess is that its WWII era for a PP or PPK, but probably is a Commercial Holster made in Germany(?). The odd thing about this holster is how the hole is in the flap, instead of the button being on the flap like every other holster of this type I've seen. The aluminum button is marked D.R.P. and Der Original Kropf. Any idea of value?