Only one of your grandfather's siblings who stayed in Norway married. Lars, born 1888, married Marta Meland b. 1889 and lived on Haavarsholm in Sveio. They had 4 children:
Brita 1925-, Haldor 1927-, Einar 1930- and Klara 1932-.
Source: Gards- og ættesoge for Sveio. Vol. II. / Simon Steinsbø, 1987.
Haldor 1927- took over the family farm in 1963: http://www.gulindex.no/p/Haldor_S%C3%A6vareide/393485