The Antipodean Hammer

The Antipodean Hammer is a side quest activated by either talking to Cutter at Cutter's Weapons in Crucible, Dumag gro-Bonk at The Missing Pauldron in Bliss or by finding a Matrix. To buy armor from Dumag or Cutter, you need a certain amount of Amber for Dumag or Madness ore for Cutter. Amber can usually be found inside Gnarls or hollowed out amber stumps usually found in caves. Madness ore can be found on Grummites and from Madness deposits found in fort ruins. There is a list of how many pieces of ore pieces each piece of armor or weapon needs on the wall above the table, between the two armors on display. They will also tell you that you can make the armor and weapon magical and for that you'll need to find matrices.