After further review, I see that your find (Folktales of Norway By Reidar Thoralf Christiansen, Pat Shaw
Iversen/Translated by Pat Shaw Iversen) was more help than I originally thought.
Within it (as separate stories) are excerpts from the full length folktale, "Berte's Tuppenhaug". So it has been translated, just broken up in to shorter stories in the retelling. The "Interrupted Huldre Wedding at Melbustad", and "The Man Who Became Huldren" in the work you found, are part of the 'not translated' Norwegian fairytale that we both located on line. There may be others as well. But, I did easily identify those two, in the auto translated version.
So once again, thank you very much. My own research was too narrow in scope; you nailed it for me and the original author of this query.
I was searching for information on the same to assist in identifying & documenting the ancestry of Mads Olsen, Ole Madsen, Christian Olsen, & Carl Christiansen in Norway.
Your find saved me, and I'm sure others, a great deal of time. It is so appreciated!