The title refers to the House of the Seven Gables, a Salem, Massachusetts landmark, which was immortalized in the 1851 novel written by American author Nathaniel Hawthorne.
The Nordic name "Gunnar" means "fighter, soldier, attacker" with further connection to the words "brave and bold." However, this is the name of Prof. Ericson's servant, to whom the word "loyal" is applicable far above these other adjectives.
The Fjord mentioned in this episode is described as the deepest and narrowest in all of Norway just happens to match the description of the actual Sogn Fjord in Norway.