Klaus, again thank you for the information. Yesterday I made a search on the internet and I found some useful information regarding the Württembergisches Dragoner (Dragoon) Regiment Nr. 26.
I am also searching the Anson Batt, which is also very interesting, it seems that the two of them faced each other in the trenches 1914, but I am still searching for more details.
Thanks to you this Erfurt Holster can be displayed with a very good informative caption.
Alf.