It can only be found on Silver World on the 12 Worlds Galaxy and at the mid floor ranges in the Mugen Field on Regular Route.
Stealing from bosses will drop both their Normal (usually a random item) and Rare (usually their component) item so stealing an item from them would guarantee both their items. Using skills like Chicken Run Trap, Phantom Mirage, Eagle Shot, Reflection Ball etc will steal their normal items while Special Skills will steal their rare item.
The required components must be sold to the vendor to purchasing better items as well as earning a little bit of extra money. There is no use to keeping the components other than Silver Ingot x2 which is used for Captivating Planet Spot #3 on World of Awakening.
Components that are labeled in red, need to be found in order for it to appear in the shop.