I posted your information on a Norwegian board, and a Norwegian lady named Ann-Mary Engum from Brekstad put things together and found your family! I tried many different name possibilities, but the correct names found by Ann-Mary surprised me. She did amazing research!
"Sam Olsen" was born "Sverre Nekolaissen"
"Olaf Olsen" was born "Olaf Martin Nekolaissen"
but he is not the twin brother of Sverre. The twin is:
Torvald Nekolaissen. Torvald and Sverre were indeed both
born 15 Dec 1898.
Their parents were Nekolai Peder Olsen and Maren Jørgine
"Joan" was born "Jorund Kristiansen"
Daughter "Leviegh" was born "Liveig Elise" on 2 Feb 1921
I will add more information and posts links to the records.
I wish I could says I found this myself - but all the work
was done by Mara-Ann Engum.