Bertel Wilhelm Benson

Bertel Benson was born abt 1853 and his immigration date is questionable. Two census reports say 1855 and two reports say 1865. Both of his parents were born in Norway. My mother remembers hearing stories about him changing his name when he came to America, which might be why I can't find any immigration information on him or info from Norway! She remembers him changing it to make it easier for people in America but she’s not sure if it was his first or last name. Is there any Norwegian name that comes close to Benson that I should look for? I’ve been Bentson and Bentzen and I haven’t found anything. I need help! I’ve reached a complete dead end for him. Thank you!