Where were the `Blades of Westernesse` forged?

[Voralphion]

Maybe they used the smithies of the Noldor?

I don't see why they would've used the smithies of the elves, the dunedain were very competent at forging weapons and other things of metal and certainly could've done it themselves.
I tend to disagree that it was forged for the wars of the last alliance because I think it says it was woven with spells for the Witch King's demise. It was specifically made for the purpose of killing the Witch King, who didn't found the realm of Angmar, and hence been a direct threat, until the third age. It would've been made probablly not that long after Angmar was founded in one of the three northern kingdoms.