Here is a wrench used on German MG 08's and MG 08/15's. These wrenches were originally made in WW1, but continued through WW2 as the MG's were pressed back into service. It is a basic multi-tool, with a wrench head on one end that fits the booster assembly on the MG's and the other end has a hammer, screwdriver bit (which was removable) and pry bar.
This one also has stamps. These are getting hard to find in this condition with no pitting and all gun metal blueing still left on it.