Well,
The discussion on the local forum continues, so I took the liberty of uploading some additional Mauser material.
The former Konigliche Gewehrfabrik was located in a Monestary in the center area of Oberndorf. The Mauser brothers took it over in 1874 and this was the start of the Mauser gun factory.
Several new sites were erected around Oberndorf during the years that followed, before WW1.
From the 1938 company history, the plant images date from around 1910:
The 'Ausseres Werk' (the 'external plant', named as it was located outside of Oberndorf).
The 'Oberes Werk' (the 'upper plant' , as it lay just a bit higher on the hills surrounding Oberndorf).
The 'Mittleres Werk' (the original monestary):
The interior of the monestary chapel. The chapel was in use as a weapons display room, the 'Waffensaal':
The monestary survived the war and the chapel was restored to it's pre-factory state. In the building next to it, the present Oberndorf Weapons museum found a place.
(source: Oberdorf website:
www.oberndorf-neckar.de)