Wow! A real storybook holster.
The maker's mark is AWM/9/13...Artilleriewerkstatten München/work group 9/1913
The first unit of issue was the 6. Chev marking, which would be the 6th Chevaulegers Regiment (a cavalry unit) that I think was part of the 5th Bavarian Infantry Division.
The later unit of issue looks to be a Weimar era marking for the 4th Eskadron, Reiter-Regiment 17 (a heavy cavalry unit), weapon (inventory) number 40. I could be all wrong on this one as my knowledge of Weimar era markings is shakey at best
(I could be dead wrong on both of them!
)