rameshji thanks to share a rare stuti of lord somnath mahadev,
i think you perhaps never visited this land, the nyamkumati as you stated in your attechment is a river having distance around 40 km from prabhas and the said kuber nagar - now a days known as kodinar city and the ancient nyamkumati river (one stream of vedic sarasvati -- पञ्च नद्यः सरस्वती मपियन्ति सस्त्रोतस: शुक्ल यजुर्वेद ) today known as shingavado river. even today there is a small temple in the kodinar village on the bank of river is known as somnath.
agreed that this is stuti for lord somnath but little difference is stated above.
i can write this way because i belongs to somnath - prabhaas. and i am atteched with ritual works as a brahmin.
sincire request to you also if you have prabhas khand of skanda purAn kindly bless me by giving a digitised copy through this forum. i have rest all volumes of skand but missing the one of my homeland.
regards and thanks again,
kamalesh pathak