Folks,
"Fortress" Lugers are Lugers marked as being issued to "Fortress" troops. They are not a separate type of Luger, just a Luger with different unit markings. Fortress Troops were what we in the US Army would classify as HQ Command soldiers assigned to a garrison proper vice being assigned to a unit which was tennant at the garrison.
Many of the fortress units were Minenwurfer and machine gun detachments, as well as the usual assortment of cooks, clerks, etc.
Tom A. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />