http://gw.gamewikis.org/wiki/Quartermaster
In Factions it was easy to find the quartermasters as they were always located in that regions main town, and had quartermaster in their name. But for Nightfall only the Istan quartermasters have "quartermaster" in their name, and only the ones for Vabbi and Realm of Torment are in the main towns (though the ones in Kourna are just outside it and The Desolation doesn't actually have a main town).
So I'm proposing two changes:
1 - Put [Collector] at the end of all the quartermasters names.
2 - When you hover the mouse over a quartermaster item, the popup tells you what NPCs to trade them with, and where they are located.
some changes to the quatermaster system
bilateralrope