Adding web site source and time ago to aggregator block

Hi,
I guess this should be rather simple, but I can't figure it.

In template.php I added this aggregator theme override:

/**
 * Format an individual feed item for display in the block.
 *
 * @ingroup themeable
 */
function Nanovip_aggregator_block_item($item, $feed = 0) {
  global $user;

  if ($user->uid && module_exist('blog') && user_access('edit own blog')) {
    if ($image = theme('image', 'misc/blog.png', t('blog it'), t('blog it'))) {
      $output .= '<div class="icon">'. l($image, 'node/add/blog', array('title' => t('Comment on this news item in your personal blog.'), 'class' => 'blog-it'), "iid=$item->iid", NULL, FALSE, TRUE) .'</div>';
    }
  }

  // Display the external link to the item.
   $output .= '<a href="'. check_url($item->link) .'" target=\"_blank\">'. check_plain($item->title) ."</a>\n";

  return $output;
}

this is what formats the aggregator block link.

Looking in the aggregator code, I found these codes:

<span class="age">'. t('%age old', array('%age' => format_interval(time() - $item->timestamp))) .'</span>

Which output age old since fetched.

And:

<div class=\"feed-item-meta\">$source <span class=\"feed-item-date\">$source_date</span></div>

which (i think) adds a link to source.

I try to add these code to

 $output .= '<a href="'. check_url($item->link) .'" target=\"_blank\">'. check_plain($item->title) ."</a>\n";

from the portion of code above to add to this line source and age old time, but it never displays correctly. Sometime it remove the blogit icons for example.

So how should I format this last line to include correctly age old and source ?

Cordially,
Brakkar