WWI P08 Luger holster 1912 help with identifying maker

[Tshnabs]

Recently picked this holster up in a grouping. Having a lot of trouble identify the maker. Dates 1912 with what Looks to be J.B. Something 2 and another marking of R.J.R. 52 or 53. Thank yo for any help

[Kohima]

The ’J.B. something 2’, you refer to, appears to be J.R.52 (infantry regiment 52).
This is repeated to the right, with an additional ’R’ (in a more floriated font), to indicate the reserve regiment - Reserve Infantry Regiment 52 - perhaps suggesting a later transfer.

[Tshnabs]

Looks like it could be “F. Cobau BERLIN”