Beth, have you made any progress since August in your search about your Ranner line in Graz?
The parish of St. Joseph is far away from Gösting. A possible connection would not be evident for me.
The City Archive (which is under the direction of Dr. Strahalm) has other documents that could help. For instance, they have the full census data of 1910, also the residency records ("Meldezettel"). The problem might be that, as far as I know, Gösting was not yet part of the city proper of Graz at that time. What was the event in 1910 to which you seemed to refer? If it was a child birth, the City Archive has the so-called midwife reports of the births they assisted. If it was a death, there is a civil registry, besides the record written at the parish.