If you are truly trying to do a repository, then you need to make the repository not extend EloquentItem.

interface ItemReposistory
{
    public function find($id);
}

class ItemServiceProvider extends ServiceProvider
{
    public function register()
    {
        $this->app->bind('ItemRepository', 'ItemRepositoryEloquent');
    }
}

class Item extends Eloquent
{

}

class ItemRepositoryEloquent implements ItemRepository
{
    protected $item;

    public function __construct(Item $item)
    {
        $this->item = $item;
    }

    public function find($id)
    {
        return $this->item->find($id);
    }
}

class ItemController extends BaseController
{
    protected $item;

    public function __construct(ItemRepository $item)
    {
        $this->item = $item;
    }
}