I found a solution by eliminating the Custom Post Type and adding a Theme Options page with a textbox to add/edit the default banner content. Ian Stewart has an awesome, easy tutorial on creating Sample Theme Options. He explains how to make it work with a child theme. (Thanks, Ian!)
Here is the what ended up going into the header.php file. Hope this helps someone else.
<div id="headline">
<?php
if (is_page()) :
$headline_custom = get_post_meta(get_the_ID(), 'banner_headline', true);
echo $headline_custom; //Show the custom headline from METABOX
else :
$options = get_option('sanskrit_theme_options');
echo $options['headline-default']; //Show the default headline from THEME OPTIONS PAGE
?>
<?php endif; // end check for metabox ?>
</div> <!-- #headline -->
