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Mauser pistol made by Josef Nickl in Oberndorf date subsequent to the 1914 and previous one to the 1920. It owns numeration uneven of two digits and alternate with the pistol Mauser Nickl " II" . Furthermore it counts on evident mechanical differences with respect to the same pistol.
Example of numeration
to mauser Nickl " I" 2n+1
to mauser Nickl " II" 2n+2