The earliest Liebenstein in church records MAY be Casper Lybenstein who was the godfather at the baptism of Regali, daughter of Hans Schmidt von Riplen on 21 Feb 1527!! I found this record in the baptisms and marriages of the Evangelisch-Reformierte Kirche Grossmunster Zurich (FHC INTL Film 922691)
After finding the Lybenstein and Liebenstein families in the microfilm records of Albisreiden Evangelisch-Reformierte Church, I was curious to look for family members in the other Evangelisch-Reformierte churches in Zurich during the 1500s. The records for the Grossmunster Zurich Church begin the earliest. The other two were the Frauenmunster Zurich and St. Peter Zurich churches. After 6 hours of looking at microfilm, I found the name Lybenstein or Liebenstein in only two records. The one above in Grossmunster Church and one in the Frauenmunster Church for the marriage of Elfi Libenstein to Mathis Rigardt in 1536. I could search only a few years in each one, so there are probably more.