Hey folks. I just ran across this utility that allows you to view and edit the overworld maps for DW2-4, and also view, but not edit DW1 map. This should make it real easy to very quickly make a map for DW1-4's overworlds. Otherwise it would take ages to snap each screen. You can view at one time large areas of the map. I mean, you will prolly need to take a snap of a large area, then scroll the map in the editor some, and take another snap of it.
Here is the link to zophar with that utility.
http://www.zophar.net/utilities/neslevel/dragon-warrior-x-overworld-editor.html