My Grandparents

My grandparents, John Hendrickson and Martina Davidson Hendrickson were both born in Norway between 1880 and 1884. I have found my Grandmother, who was Martina Davidsdatter (1883) born to David Stenson (Stenesson) and Solveig Larsdatter at Rondestveit (later lived at Kvitnes farm), and have found her birth record. I have not been able to find John Hendrickson (his American name) as I don't remember where he was born or what his father's name was. What can I do? I know he was from around Bergen, possibley from an island community, and that he was the youngest of the family. He left Norway sometime around 1903, ended up in Valley City North Dakota, where he met and married Martina. They moved to Southwestern North Dakota and homesteaded a farm south of the town of Rhame, where I grew up. Grandma had several brothers that lived there. plus one sister, Bertha, who married a Nils or Nels Jensen, Her brothers were John, Knute, and Ingebrigt Davidson. They left a brother David in Norway, and I think a sister Gertrud. Any and all information would be appreciated. My Aunt Mardy, (Martha Dorothy Louise Hendrickson Tatro Merwin) would like to know if I have any luck before she passes on. thanks