this marking? Been reading a lot, trying to learn unit markings as good as most here. Sorry for the photo smallness.
2.E.M.G.IX.35
First I thought it was an Eisenbahn MG pistol but the IX was something different and then I came up with:
2nd Ersatz-Machinengewehr-Kompanie 9th Army Corps weapon #35
Any other stab at it?