You don't want to change those, you just need to add the $order->products[$i]['id'] to the display around line 171 ...

Put the file back to how it was and try this change to see the products_id show ...
PHP Code:
           '        <td class="dataTableContent" valign="top" align="right">' 'ID# ' $order->products[$i]['id'] . $order->products[$i]['qty'] . '&nbsp;x</td>' "\n"