That strange 6/8-beat has been labeled "Alpine swing" by some who earn their living performing / promoting / developing that music. (I´ve heard an "Egerländer"-tubist use that Expression). It´s supposed to imitate a horse´s slow walk rhythm.
The pro bands and those participating in contests have fun highlighting certain passages by well syncronised, extreme tempo variations. Some put their drummer in the front row, especially if they perform without conductor.
More sources of repertoire can be found at Musikverlag Rundel
http://www.rundel.de/ . Also search for "Böhmischer Traum" by composer Norbert Gälle. Originally performed by "Scherzachtaler Musikanten". See if You can find a live video on Youtube. Good stuff.
Here´s another of his titles:
http://www.youtube.com/watch?v=EakyXKeh2uY Fun-to-watch conductor.
Interesting to the connoisseur: Gottlieb Weissbacher, leader of "Die Fidelen Inntaler" from Tyrolia. Composed classics like "Fuchsgraben Polka", "Martscheiner Marsch" and lots of others.
Peter Schad and his "Oberschwäbische Dorfmusikanten"
http://www.youtube.com/watch?v=Yk77R56w3W4