At first glance this guitar looks like a Hauser Vienna model, but it is not. Rather, it is a unique hybrid of Spanish and German construction ideas. Built shortly after examining Segovia's 1912 Manuel Ramirez  and  Llobet's 1859 Torres, the influence of these Spanish luthiers is clearly evident its Spanish style bridge and its plantilla, whose dimensions are very close to Miguel Llobet's 1859 Torres.  Its body depth is also more like  a Spanish guitar,  although it is slightly thicker in the middle than the ends, like the Vienna model. The German heritage of this guitar is clearly visible in its general appearance. It has a floating fingerboard, zero fret, and the bolt on neck that can be removed with a key, making  it easy to shim the dove tail joint, and adjust action by changing the neck angle. 

We can speculate that Hauser may have built this hybrid one of two reasons. One, it was a kind of scientific experiment to systematically test the key features of the Spanish fan braced top (hence the shape, bridge, and bracing) while keeping its construction constant. The other is that he was experimenting with ways to improve the German design. Regards of his reasons, the result is a instrument whose sound is typical of  Hauser's Spanish guitars.