Hello, sounds like a cool project. The order is based on the file names. So if you call the .sav files:

adventures_in_architecture1.sav
adventures_in_architecture2.sav

That should work nicely.

The actual display names in the menu is set by the "saveName" and "mapName" variables inside the file.

If you want proper campaign behaviour then add a hyphen before the number like this: adventures_in_architecture-1, adventures_in_architecture-2.

This will make it so the second level cannot be started until the first level has been finished. This approach has a few bits that can go wrong if you don't have things set up right though, so to start with I recommend avoiding the hyphen and treat each level like a standalone map.

Hope that helps!