He looks to be a very German WW1 era or just post-war officer. Try posting that image on the Great War Forum. Scott
He'e s an NCO from the early "Weimar Republic" era (1919 - 1933). The oak leaf insignia on the collar is somewhat special, though...
It is not a regular feature of the collar insignia for an NCO - at least I have never seen it. But this is early Reichswehr still using WW1 uniform elements - the new uniforms have not been designed or issued yet. So, maybe some improvisation?