This merchant is not where he should be. Should be inside Adaman Armor in Neriak Commons . He sells block of medium quality ore, used to eventually make fine plate armor for Dark Elf crafters. He is not anywhere in the zone in fact.
Location says he should be there according to both ZAM and the P99 Wiki, so have no idea where hes at..
http://everquest.allakhazam.com/db/npc.html?id=9960
http://wiki.project1999.org/Treven_Ru%60Soe