You mentioned a few names; however, your spelling is highly inaccurate and you must find out the correct spelling from original documents.
Nick George (In this case, it is nor a "real" name. As I said, IN THIS CASE it means Nick, George's son. Towards the end of 19th century, "George's Son became "Georgiou", especially in Cyprus. Id not believe that this applies to your case.
Mary Keleay (probably the document shows the name Keleoy (oy = ou) = Keleou. There are no Greek names that are close. The closest is KELLIS.
Elaine Coulea is probably Eleni Koulas
The last is the easiest, Helen Mamoley = Helen Mamoli(s) (Mamoleou)
Mamoli is a well know Venetian family that migrated to Crete before 1400. There were at least 5 Notary in Crete between 1560 - 1650 with that name.