luger holster

I have a luger holster marked on the back as follows-

AUWAERTER&BUBECK WaA101 under an eagle 1934


AG


STUTTGART

Inside the flap is the usual takedown tool pocket but this pocket has a second flap over it.

Parellel to, but off to ths left and under the takedown tool pocket, is a leather loop about 2" long.

What is the purpose of this loop and the second flap over the takedown tool pocket?

I also have a brass cleaning rod, 24 1/2 cm. long, a loop in one end and an oval crest with the letters HWC in it.Below this is the letter D.It came with one of my luger holsters but it fits nicely in the pocket on the front of my broomhandle holster. Is this where it belongs?

Also, what book on German holsters would you recommend for someone like me who is not a real luger collector but has aquired 6 of them and 5 holsters?