I've found some military "things": US belt and ammo pouch and a mystery pouch. In a french Forum, someone told me that's a german double pouch for Stielhandgranate and fot fallschirmjäger . According to this blog, it can be true... but I can believe it!
There is no marking, except a little bluish mark inside just below the zip.
What do you think about thit pouch?
the "Riri" zipper
thank you for any information :-)