There seems to be a lot of confusion with this surname because of the name changes. I have seen Blosmo, Blasmo, Blosmoe, and the spelling that my family uses today, Blosmore. I am related to Albert Blosmo who was the son of Albert and Elizabeth.
My grandfather told met that Albert's real father was someone named Jack Hennessey or something like that. Andrew adopted the children and they all changed their last name to Blosmo though not legally. Legally, my great grandpa's last name is Hennessey. Since most of the people are not alive, nor do I have contact with any other Blosmos, I cannot verify this information.
Regarding Andrew Anderson and Andrew Blosmo, I believe that Mr. Anderson was Mr. Blosmo's father-in-law. Though it is weird that they are both from Norway and Elizabeth was born in the US. I'm not sure but if anyone can clarify, that would be great!