I checked a copy that has been scanned into the Petrucci Music Library, and it has a C#. This was only the harp part however. (I didn’t want to go through the score for the entire opera!).
I remember that Professor Elizabeth Richter did an extensive editing of the harp parts for that. We used copies from the Metropolitan Opera House in harp class, and they were a complete mess, with so many decades of fingerings and pedalings. You could never get a clear view of it that way.