Well, I can't think of any Welsh sources off hand that specifically point to a Norwegian connection for the tune. Huw Williams who wrote pretty comprehensively on Welsh folk songs wrote, (in translation)"It is not know what the tune is, except that some Welsh hymn tunes have left a heavy mark upon it."

Having said that, there was a lot of 'borrowing' of tunes from Scandanavia particularly at a time when the sailing ships were still plying the waves to harbours in North Wales where lies the roots of the song.

sian, west wales