I suspect the lads in this photo are not Germanicon but from one of the Baltic states, just after WW1.

I recall that a copuple of these short-lived countries were equipped with a motley assortment of stuff to "kick-start" their forces. There are photos showing troops wearing German uniforms and helmets (of several late-war styles, and armed with P-14s and Vickers gun). Can't say I remember MG-08 sled mounts, though.

About three years ago, I saw what I believe are two of those P-14s in the hands of a collector in Queensland, Oz. They have a small, about 13 x 40mm brass plate on the right side of the butt. And the bores were atrocious.