After reading the article I'd still say Christopher Columbus, aka Pedro Scotto, was Italian, just of Scottish descent. His alleged true family surname, Scotto, looks to me as if it means something like 'the Scot' in Italian (guesstimating because I never learnt Italian). It certainly doesn't look like a Scottish name. In many countries (but not Gaelic ones so much), one of the early forms of surnames indicated the town where you were born, or if you were a foreigner, the country. If his parents owned a shop in Genoa, they may have been born in Scotland, or their forebears may have been, but he was probably born in Italy.

Wonder if he had a claim to belonging to a clan? Probably not. As the son of shopkeepers more likely he was of lowland descent, and they would have regarded highlanders and clans as barbaric at that time, LOL!