It's recommended to rename the world file instead of deleting it. In case you need the original later.
For example, you can rename it something like IslaParadiso.world.original
You will get a message that the file will become unusable. It's okay to make the change. It won't hurt it. As to use it again, you delete the .original and it will be as good as new.
I don't have Ella's fixed IP world file, but here's my example with Sunset Valley original file and Ella's fixed SV world file.
Click images to see larger view.
Renaming the original world file:
Both the original and fixed world files:
If you rename the original world file and want to use it again. Notice the different file sizes.
Ella's Fixed World File is: 85,726 KB
Sunset Valley.World.original is: 78,403 KB
You will want the file that is 78,403 KB and rename it back to Sunset Valley.world.