[DonVoigt]

There is a list of the Heerszugamt locations in one of the books, they are a "smaller" organization you mention; I would think the WMg10 is a similar depot or some such smaller repair location.

Or another way to put it is the Eagle/Mg10 is similar to the HZaIJ type marking of a small unit of he supply/repair system. The HZa with letter/numbers is seen on parts and pistols.

Could beE/WMg10 thought marking "everything" was a good idea and used there stamp promiscuously - including on leather(and were the only depot to do so-in spite of no "orders" to mark leather goods).
I believe there are 3 or 4 observed E/Mg10 marked holsters mentioned in this thread alone.
So rather than "it can't be that"- it could possibly be that. JMHO
JMHO.