Deutsch Gerisdorf is in middle to southern Burgenland, near Lockenhaus. It is not really close to Vienna. Salmannsdorf is indeed another neighbor village of Deutsch-Gerisdorf.
Check out the Austrian on-line phone directory at www.etb.at
and enter Schermann as name, and Deutsch Gerisdorf as place, and you will find quite a few Schermanns who still live in the village.
You need to touch base with the Burgenland Bunch, a web-based support group interested in the Burgenland. The bb's homepage is at http://www.spacestar.com/users/hapander/burgen.html
Check their member list and you will find several people who search the name Schermann, among them members with family roots in Deutsch Gerisdorf.