Activate Krark-Clan Ironworks by sacrificing Sword of the Meek, adding ({C} magic symbol) ({C} magic symbol) .
Sword of the Meek dies, triggering Slagstone Refinery, creating a tapped Powerstone token that enters the battlefield as a 1/1 creature due to March of the Machines and Unctus.
Sword of the Meek triggers, returning itself from your graveyard to the battlefield, but not attaching itself to the Powerstone due to Sword of the Meek becoming a creature.