You can import the existing template fields into the new areas by using the area admin under the gear icon.

1) Go to the "Manage Site Areas" admin under the gear icon
/cms_admin/areas.php
2) Locate the new area entry and click edit
3) Scroll down to the bottom and locate the "import template fields " and select the area you wish to import from and click "Save Entry"

That will import in the old areas template fields to the new one.

If you need to locate the ID of the new or old area, you use the &highlevelcachedebug=1 or ?highlevelcachedebug=1 for the area to see the area ID (About half-way down the results page).

Let us know if you have any other questions or if you run into any issues.