Axel Berntsen, Brooklyn, ny

I have been searching for Axel Berntsen, born 1883 Arendal, Norway. He immigrated in 1910. He married Josephine Pedersen in 1913 in Brooklyn. On his marriage certificate in Brooklyn he lists his parents as John Berntsen and Elisabeth Andersen There is a WWII draft registration in 1942 showing him born Jan. 19, 1883 in Alendel (which probably should be Arendal). He was naturalized in 1938 at US district court in Brooklyn. His social security application shows him as Axel Wilhelm Berntsen b Jan. 19, 1883, and his parents as Berent Johan Ericksen and Marie Elisabeth Andersen on Feb. 9, 1937, and place of birth as Arendal, Norway. He is on the 1915 NYS census in Brooklyn, and on the federal census of 1920, 1930. They show his parents being born in Norway. I've searched Digitalarkivet and cannot find Axel or his parents anywhere. Neither the census nor the Arendal birth records show anything. Hopefully someone will be able to help