Twine stores the project’s Name and its associated unique IFID (along with other project information) in the attributes of the
<tw-storydata> element that is contained within the Story HTML files you generate. The same element is also contained within your Twine 2.x project HTML files.
The file-name of a Story HTML file has no effect what so ever on a project’s Name, this is why renaming a Story HTML file has no effect on the name of a project when you import it into the Twine 2.x application.
eg. the following is an example of such a
<tw-storydata name="Test SugarCube Project" startnode="1" creator="Twine" creator-version="2.3.8" ifid="04BA0C91-E1DD-4691-B1FE-BE8802441FA4" zoom="1" format="SugarCube" format-version="2.30.0" options="" hidden>
/* ... the project's Passages and other elements... */
<tw-passagedata pid="1" name="Start" tags="" position="350,100" size="100,100">The first Passage of the project...</tw-passagedata>
You need to manually edit the Name and unique IFID if you want to create a 2nd project from an existing Story HTML file.