see if this helps
Civfanatics: Utilities: 'Unofficial' Civ3 Scenario Editor
I uploaded this to the server and i when testing it found that you can only edit .sav game files from v 1.17 or lower, but it does allow you to modifiy the .sav game files.
If this doesn't work
Click THIS and see if any of the other files uploaded will work, i remeber when i was uploading them that several had import .sav game files but that was mainly to change gold, force building, etc.