Found on "a steamwork shock striker" on the way to Rusty Gnomework - dropped within 20 minutes of killing Rusty... tried 5 minotaurs with no luck, this striker was in the last group with last minotaur.
Just so you guys know, I looted the bracelet off of a Mechanic today. Seems that you will have the best luck killing things that are in the 'area' of the Rusty Gnome guy. For me, I got it on 10th kill in Southeast room from the Rusty guy that you kill.
*Edit* Dropped from a minotuar shocktrooper just on the other side of the wall behind the Rusty Gnomework... (Thanks Hoheyd for the heads up!) *Edit*
Is this a really rare drop or what? I've been here for a few hours killing all around the Rusty Gnomework and haven't seen one. Another person here has been here for 5+ hours w/o any luck either.