As I have been searching for EVENSON, HALVORSON, RUMUNDSTAD AND JOHNSON (from Norway)I have discoved their system of naming, which continued til 1900!!
If your guy was Even Olson; his son's surname would be Evenson (son of Even.And from Even's name I can tell his father was Ole something as his (Even's) surname is Olson (son of Ole)And Hans son would probably have the surname of Hanson.
Now let me tell you it is not easy to follow these Norwegians!!