Hi Yehuda,
you can try with a group called "RE : MEMBER VIENNA"  (look on facebook)
this is a wonderful group of young volunteers who takes care of the  Zentralfriedhof cemetery .they clean, cut the overgrowing plants covering the graves,etc.
I gave them a location of my great grandfather's grave  and they sent me a picture of it !!!
the person to address there is Wilhelm Ido Perry Alter


Dorit Sela, Israel
seladorit@...