Carol, I can only help you with the spelling, I'm afraid. Cshippermust be Schipper, it might also be Schippers or "de Schipper". It is a very common name in the Netherlands, only in Haarlem you will find 115 Schipper's (http://www.detelefoongids.nl). Zandvort must be Zandvoort, a seaside village at the North Sea, near the city of Haarlem (not Harrlem), 30 kilometers west of Amsterdam. The name Geaukoop could be Goedkoop (4x in Haarlem), or Goekoop(you use the French "eau" in the name). The use of English or American first name, like Joan or Dorothy became only popular after WW2, the Dutch version would be Johanna, or Jo, or Hanna. Good Luck with your search.