Nils Paul Xavier, Amanda family emig 1873

Seeking any and all information on Sami/Norwegian Nils Paul Xavier family (great-grandfather) , his wife Amanda and two sons, Karl (my grandfather) and Johan (great uncle) who emigrated in 1873. I am working both personally and professionally on family history, especially from the Sami viewpoint. They came to USA in Sept of 1973. Nils Paul was godson to Paul Gaimard and Xavier Marmier who were leaders of Expedition Scientifique du Nord in 1838-39 (visit to Kautekeino). I will later post some items that may help in gaining clues. Thanks in advance to anyone corresponding. Anyone can send materials in English or French (fluent in both). I apologize for not knowing much Norwegian. Takk! Merci! Thanks! John E. Xavier