ask at diocesanarchive Klagenfurt:
http://www.kath-kirche-kaernten.at/dioezese/organisation/C25...

there are still people with this lastname.
3 hits at phonebook for Hirzbauer in Carinthia:
http://www.herold.at/telefonbuch/k%C3%A4rnten/hirzbauer/

124 hits for Riegler in district Wolfsberg, Carinthia:
http://www.herold.at/telefonbuch/wolfsberg/riegler/
51 hits for Riegler in Lavamünd, where Weißenberg belonges:
http://www.herold.at/telefonbuch/jQhzT_lavam%C3%BCnd/riegler...
http://de.wikipedia.org/wiki/Lavam%C3%BCnd
http://en.wikipedia.org/wiki/Lavam%C3%BCnd

46 hits for Salzmann in district Wolfsberg:
http://www.herold.at/telefonbuch/wolfsberg/salzmann/