Is there any way to access the Artisan of Steel?

Well, before I could turn in my Talisman for the reward I was disconnected from the game and when I got back in I was just in the regular town and not able to get back into the area. Do I need to contact GW support or is there some way to get back into the area or find the NPC?

Simply beat Hell's Precipice again, you'll end up in that zone again.

The endgame zones of all the campaigns and EotN work the same way. You have to beat the final mission every time you want to visit the zone. This isn't much of a problem for Factions and EotN, since it only takes a couple of minutes, and not that much longer for Nightfall. Unfortunately, Prophecies is a real pita, though at least you can skip the bonus.

Remember that you can buy gold inscribable versions of the wep's that they offer, they cost a bit, but might be worth it