http://everquest.allakhazam.com/hist...es-2001-1.html
Jan 2001-Jul 2001 patch notes state "Fixed The Iksar Shackle Of Steel Quest"
Implies, clearly, it was in game by this point.
Master Rinmark ("An Iksar Master" in Timorous Deep) does not respond to quest dialogue, though this may be a faction issue? Human monk, warmly.
Quest mob in Frontier Mountains (An Iksar Slave) does not appear, either.
/shrug just sayin
Most of this info, noted, is web-based. Have no previous personal experience with this phase of Shackle quest line, admittedly.