Hitlerjugend m7/13 Arthur Schuttelhofer & Co

[chuck303]

I had been offered this post 1938 without motto Arthur Schuttelhofer & Co knife. Looks decent. I have had others by same maker in the past, but none like this with an etched rzm marking rather than stamped into the metal. Is this a variant known to exist? I have not seen one with etched marking before so i wonder if this is a mid or late war method used to mark their blades?