Pete,
* The holster's maker, sans umlat(s), is "Vereinigte Fabrikanten/fur Militarlederzeuge/ G.M.b.H/Soligen.' which I very loosely paraphase as: "Association for the Fabrication of military leather item, Inc., Soligen"
* John Walther, "The Luger Book", Pg. 282, Item, V9iii. His reported example was dated 1915 and supposedly had an "S" in a triangle as the trademark stamp. Since 1916 follows 1915....maybe a "T" in a triangle followed an "S" in a triangle Trademark. More likely, the "S" and "T" indicates which firm within the Association actually was responsible for the item marked.
* My 2 centavos for a starter.
Respectfully,
Bob