Daf Yomi Nedarim 55a: Nehar Pakod or Nehar Pania? Or Harpania?

In Nedarim 55a, from my Rif translation:

בר מר שמואל פקיד דליתנון תריסר אלפי זוזי מעללתא דנהר פקוד לרבא

The son of Mar Shmuel ordered that thirteen thousand zuz worth of alalta {=the Aramaic equivalent of tevuah} from Nehar Pekod {our gemara: Nehar Pania} should be given to Rava.

Based on the principle of lectio difficilior, it would seem that Nehar Pania, as we have in our gemara, is correct and original. We know Nehar Pekod from elsewhere. It appears 15 times in Babli (10 times as miNehar Pekod, and 5 times as deNhar Pekod), and twice in Yerushalmi (as miNehar Pekod, in the same fascinating story). It most likely crept into the text here as accidental repetition of the earlier verb פקיד, and was a known and recognized place.

Soncino tells us a bit about Nehar Pania:

[Harpania, a rich agricultural town in the Mesene district S. of Babylon situated on a hill and canal. Obermeyer (op. cit.) p. 198ff.]

It seems that he is interpreting this as without the nun. Just Harpania. We find mention of Harpania elsewhere, in Nedarim daf 17a:

יתיב רב המנונא קמיה דעולא וקא הוי בשמעתא אמר מה גברא ומה גברא אי לאו דהרפניא מאתיה אכסיף א"ל כסף גלגלתא להיכא יהבת א"ל לפום נהרא א"ל א"כ מפום נהרא את
מאי הרפניא אמר ר' זירא הר שהכל פונין בו במתניתא תנא כל שאין מכיר משפחתו ושבטו נפנה לשם
אמר רבא והיא עמוקה משאול שנאמר (הושע יג) מיד שאול אפדם ממות אגאלם ואילו פסול דידהו לית להו תקנתא פסולי דהרפניא משום פסולי דמישון ופסולי דמישון משום פסולי דתרמוד פסולי דתרמוד משום עבדי שלמה והיינו דאמרי אינשי קבא רבא וקבא זוטא מיגנדר ואזיל לשאול ומשאול לתרמוד ומתרמוד למישן וממישן להרפניא:

R. Hamnuna sat before 'Ulla and was engaged in discussing a traditional law when the latter remarked, 'What a man! And how much more important would he have been had not Harpania been his [native] town'! As the other was embarrassed, he said to him, 'Where do you pay poll tax'? — 'To Pum Nahara', the other replied. 'If so', 'Ulla said, 'You belong to Pum Nahara'.
What [is the meaning of] Harpania? — R. Zera replied: A mountain whither everybody turns. In a Baraitha it was taught: Whosoever did not know his family and his tribe made his way thither. Raba said: And it was deeper than the nether-world, for in the Scripture it is said, I shall ransom them from the power of the nether-world; I shall redeem them from death, but for the unfitness of these there is no remedy at all; the unfit of Harpania on account of the unfit of Meshan, and the unfit of Meshan on account of the unfit of Tarmod, and the unfit of Tarmod on account of the slaves of Solomon. Thus it is that people say, 'The small kab and the big kab roll down to the nether-world, from the netherworld to Tarmod, from Tarmod to Meshan, and from Meshan to Harpania.

If so, perhaps to make Nehar Pania work, we would have to drop the nun of nehar as well as the space between the words.