Guild Wars 2

The Nuhoch vendor at order of whispers camp sells ley-line core weapons. I have the required mastery but can’t figure out what else I need to do to get them unlocked. I’ve googled and wiki’d but I haven’t found a clear concise answer that helps. I would appreciate any help.
Thanks!

Those aren’t weapons, they are items for the machined weapons collections. You unlock the collection for a weapon by buying the equivalent plated weapon from a merchant at the end of the Mouth of Mordremoth event in Dragon’s Stand.

http://wiki.guildwars2.com/wiki/Machined_weapons#Acquisition

Thank you very much!