Similar compasses were produced in different countries (Austro-Hungary, Romania, The German Empire, Switzerland and etc) and was used by German troops. This compass is missing the glass cover, so the arrows are not fixed, but the arrow points to the North correctly
The helmet was found near the village Zapadnovka (Stalingrad region). Near the place where found the helmet was a few bins (maybe they were intended for headquarters divisions). On Google maps they are clearly visible. The helmet was found on great depths, possibly earlier, it was the anti-tank ditch or trench.