Congrats to that beautiful Dussägge! I am dreaming of owning such a sword one day. I would say it is South German, Styrian or Swiss. But as Jim mentioned, they were also famous in Northern Europe. My observation from auction descriptions etc is, that those with a rectangular pommel and the style like yours are mostly attributed to the above mentioned southern region, while those attributed to northern countries are a bit different in style. E.g.:
http://www.vikingsword.com/vb/showthread.php?t=22245