The most recent Norwegian census which has been released is the 1910 -- they have a 100 year ban on publication of those for privacy protection of the living.
Some church parish records as recent as the 1920s or 1930s for some areas are available online at the Digitalarkivet website as digitized images of the original pages. Those records are open and free for anyone with Internet access to browse.
If someone also of that family searches these Ancestry/RootsWeb message boards you have a chance they will notice your posting. That's a pretty big IF. There might not be anyone in such family who has enough interest in family history to be doing such a search. It might also be useful that both Brian and I have given the Norwegian name for the man you call Ralph -- Rolf.
I do wish you good luck.