I havefound Andreas, Marie, and Lars' Norwegian birth records, but am still searching for Lars' death. I had looked for Maire at first thinking she had passed which was why Andreas was with hisAunts family, but I finally found her alive in Minnesota remarried. Now I am looking to Lars' death. I have been searching Norderhus, Buskerud, Norway where I have found the birth records, but will try next Oslo if that is were Maire was working on the 1865 census.
I have found the passenger list as suggested in the above response and believe he might have found my correct correct Marie. I will continue to looking to her to see if I can find leaving parish records to prove it futher.