I tried to look your rifle marks up in der neue stockel.
It looks like the Zella, Saxony mark from 1705.
Only difference are the round shape in the middle and the half circle at the top left.
At first i thougt this rifle to be a air rifle, seeing as it has a metal tube at the wrist of the "stock". But the barrel gauge is well.. more like a shotgun so
Without a doubt i would still say it is German.