OK. I finally got it!!!
All I had to do was to modify the show.php inside of: Omeka/Themes/Seasons/Items.
I copied, pasted and modified the “print citation” portion of the show.php and created a separate block in the sidebar for “Original Source”. And thanks to the code provided by @jflatnes in a completely different post, I was able to get some idea of what I needed to do to make it show the Contributor and Source fields.
So my code now in show.php looks like this, in the section that begins: aside id=“sidebar”
<!-- The following prints a citation for this item. -->
<div id="item-citation" class="element">
<h2><?php echo __('Citation'); ?></h2>
<div class="element-text"><?php echo metadata('item', 'citation',
array('no_escape' => true)); ?></div>
</div>
<!-- The following prints original source for this item. -->
<div id="item-citation" class="element">
<h2><?php echo __('Original Source'); ?></h2>
<div class="element-text"><?php echo metadata($item, array('Dublin Core', 'Contributor')); ?> <?php echo metadata($item, array('Dublin Core', 'Source'),
array('no_escape' => true)); ?></div>
</div>
A sample page showing what this looks like is here: