( although there was an extra entry for the entire set as well as for each of the 5 individual areas).
That's normal. The 5 individual areas are the regions sold separately as downloads in the separate X-Class product. The "World" Landclass is an area exclusive to the CD version which contains areas outside those 5 areas, such as Asia, Pacific, etc.
It seems as though all the downloaded files are version 1 from 2007. I then attempted to update the 3 regions with updates shown on the web site. The update exe programs do not work; each repeatedly gives message that "destination directory has no files to update".
The "1" means "first CD version", but the CD was released well after all the main areas were fully updated so, you have all the latest versions already, that's why the updater says there's nothing to update.