If good ol` prof Horsford was anywhere close to being right that the old word was Norbega (which Norumbega should have been an italian beautification of), there is the fact that Norvegr and Norvega probably would be written this way, since b was replaced with v later on, in slavic languages this letter b still is the sound for v.
There is also the fact that an italian map from around 1380 also has this name Norumbega, a good 100 years before the incompetent Columbus thought he found a shorter way to India…
As for being Greenlanders and Icelanders, and not Norwegians, well…
Iceland became part of the Kingdom of Norway in the 13th century, but in effect it was always norwegian (until the break up of the Dano-Norwegian union,-dating in turn from 1380,- in 1814).
All the settlers in Iceland were of norwegian descent, and Leif Eiriksson, born in Iceland, was bred in Norway.
Both his parents were nowegians, born and bred in Norway, and in fact Leifs father ,-Eirik the Red,- “discovered” and named Greenland.
Greenland was always norwgian untill 1814, and we know of no explorers being born there.
Actually, the story is that the norwegian merchant Bjarni Herjulfsson “discovered” America, by accident in the year 999.
He was en route from Norway to Iceland, when he heard that Eirik the Red had formed a colony in a large landmass to the west, about three days of sailing from Reykjavik. A new market for his merchandise thought Bjarni and set sail further westwards. Due to bad weather and lousy navigating instructions he missed Greenland, and for two weeks they saw no land , but then a wooded land was seen.
This was definetely not Greenland. There were no norwegians there…
Some of his crewmen thought they should explore this land, others said it was basically a bad idea, since they were unsure if it was inhabited, and if any locals existed,-maybe the locals were not up to any trading with them, maybe the locals preferred to kill them and just take the suff they wanted…
Anyhow, all Bjarni did was to replenish freshwater supplies from a stream on land, and conclude that he was way off course.
He finally reached Brattalid (Greenland “capital”) a couple of weeks later, and told of the land in the west.
Leif Eiriksson was a rich brat, and bought Bjarnis ship, and sailed for the land which Bjarni had aptly named Helluland (Stone-slab-land) and Markland (Arable -land/grass-land).
Leif rememebered his fathers advertisement for Greenland, it was probably warmer then, but it was still mostly icy.
So “his” land was to be named Vinland (vine-land) as an ad for migrators.
Vin is of course another word for grass also, but in the year 1000 it was mostly used for vine, as in vinegrapes.