As I mainly post obscure objects in my blog, here is another one, a leather rifle holster intended for attaching the rifle to the saddle. It was made by G&S Schumacher in Stettin (Today Szczecin in Poland) in 1916. It came together with the saddlebags in the first picture. I may write about the other cavalry items in picture 1 later.
I got this holster from Bulgaria and it has a Bulgarian war ministry stamp in it. Whether it was made especially for Bulgaria or among German gear given to the Bulgarians and then stamped by them, I cannot tell, as both occurred. Germany helped Bulgaria with lots of military equipment.
The reason was that Bulgaria was a very important ally. Bulgaria entered WWI the 14th of October 1915, on the side of the central powers, and thus solved a problem for the Germans.
Until then, sending military aid to the ottomans (Turks) had to be done by sea, a perilous journey where one could encounter enemy ships and submarines, it was practically impossible to get aid through. With Bulgaria entering the war, that changed. From then on it was possible to send military aid over land, by railroad, and a steady stream of German weapons and other aid started moving towards the Ottoman Empire. To keep that vital line of transportation open, Bulgaria had to be propped up and equipped to stay in the fight.
So, this German Cavalry rifle holster will have been part of that, along with helmets, weapons and whatnot.
I have searched, but not found a clear picture of exactly this type of rifle holster, so if anyone has one, please post in the comments below.