looking for information on Venardos, Kapsanis, or Souris

I am looking into my heritage, my great grandfather was Peter Venardos who married Diamanta Kapsanis both from Kythera. He died on the island in 1919. They had three boys Constantine who married Stravola Souris, Anthony who was killed early in life, and my granfather Verron (called John in the US). My grandfather was born in 1872 and we think his father and mother were born around 1845 to 1850. Thanks.