1466 Roselli Portolan Chart
Comparing to Other Charts: England and Scotland
Roselli does not extend his map as far north as Canepa does, and therefore "Regnum norvegia" does not appear.
That may be the same reason that the island northwest of Scotland does not appear on the Roselli map. Still there are other differences that cannot be accounted for because of the areas shown on the portolan charts. Flags appear on England, Ireland and Scotland on the Roselli portolan chart which are absent on the Canepa.
Under the magnifying glass: