The maps in the King's Quest companion changed between 1st, 2nd and 3rd editions with art style changed. The locations or names were somewhat altered between the previous maps. Peter Spear appears to suggest that maps were sent to him by Derek Karlavaegen. Its mentioned in later editions that some changes to the maps for example addition of Serenia & Green Isles to future maps reflect changes to the world due to Derek hiding information or the world being in magical flux and in some cases surrounded by barriers (magical law of "containment") The maps were replaced in a style better fitting the new artwork and the new world map and map of the Green Isles in each edition. The first edition maps are interesting as they are based on the KQ3 charts and show that period when Serenia was missing.
The maps of the first edition are based on the world charts from King's Quest III, and corresponds to its geography. Later maps changed the continent of Daventry with the addition of Serenia. The locations in Daventry and Kolyma are aligned differently in the maps of each edition. I.E Monastery in Kolyma being in the north in one and the south in the other, but this can be explained by the warped boundaries existing around the kingdoms at the time (magical "Containment"). Another noticeable difference is that the location of the Enchanted Island on the world map varies between first edition and later maps. However, Derek claims he doesn't know the exact location of that island and has placed on his maps based on rumors and hearsay.