Although the Dwemer Ruins of Arkngthand are nearby, any piece of scrap metal will do. Just before you reach the ruins, you have a bridge where you will be attacked by the battlemage Snowy Granius. Once he is dead you can find some scrap metal in a crate. Otherwise you can go halfway up a nearby hill and enter Arkngthand. Scrap Metal can be found throughout the ruin, but beware of the bandits. You can also steal one from the Mages Guild in Balmora, or you can buy scrap metal from certain merchants (such as Nalcarya of White Haven in Balmora). Return to Radd Hard-Heart with your scrap metal to complete the quest. In addition to 500 drakes, you receive five points of Legion faction reputation, and Hard-Heart's disposition towards you increases by ten points.
The Journal entries for this quest say that the Buoyant Armigers have challenged the Legion, but nearly all of Radd Hard-Heart's dialogue refers to a challenge from the Ordinators.
The following Journal ID and Index codes can be used with the Journalconsole command to manually update the quest to a certain point.
Scrap Metal (IL_ScrapMetal)
Index
Finishes Quest
Journal Entry
10
The Buoyant Armigers have challenged the Imperial Legion to a hunt. They claim they will bring in the skin of a corprus beast. Radd Hard-Heart wants me to bring in the scrap metal from a Dwemer Centurion.
100
Finishes quest
I brought Radd Hard-Heart the scrap metal from a Dwemer Centurion. With this the Imperial Legion is sure to win the hunt with the Buoyant Armigers.