Sample Code:

Create a new file called: content-salesbinder_item.php

Save this new file in the root of your theme's folder (ie. /wp-content/themes/YourThemeName/).

<article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
	<header class="entry-header">
		<?php if ( is_single() ) : ?>
		<h1 class="entry-title"><?php the_title(); ?></h1>
		<?php else : ?>
		<h1 class="entry-title">
			<a href="<?php the_permalink(); ?>" title="<?php echo esc_attr( sprintf( __( 'Permalink to %s', 'twentytwelve' ), the_title_attribute( 'echo=0' ) ) ); ?>" rel="bookmark"><?php the_title(); ?></a>
		</h1>
		<?php endif; // is_single() ?>
	</header>

	<div class="entry-content">
		<?php the_content(); ?>
		<h2>Price: <?php sb_the_price() ?></h2>
		<h2>Images</h2>
	  <?php is_single() ? sb_the_images() : sb_the_image(1); ?>
		<h2>Details</h2>
		<?php sb_the_custom_fields(); ?>
		<?php wp_link_pages( array( 'before' => '<div class="page-links">' . __( 'Pages:', 'twentytwelve' ), 'after' => '</div>' ) ); ?>
	</div><!-- .entry-content -->
	<footer class="entry-meta">
		<?php edit_post_link( __( 'Edit', 'twentytwelve' ), '<span class="edit-link">', '</span>' ); ?>
	</footer><!-- .entry-meta -->
</article><!-- #post -->

Modify the "index.php" file to check the "Post Type"

This is a snippet to show how you can modify the index.php file to check the Post Type and use the new file we created above.

<?php if ( have_posts() ) : ?>

	<?php /* Start the Loop */ ?>
	<?php while ( have_posts() ) : the_post(); ?>
		<?php
		if (get_post_type() == 'salesbinder_item')
			get_template_part( 'content', get_post_type() );
		else
			get_template_part( 'content', get_post_format() );
		?>
	<?php endwhile; ?>

	<?php twentytwelve_content_nav( 'nav-below' ); ?>

<?php else : ?>

Do the same thing for "single.php" and "archive.php"

These are also snippets of how you could modify the other files.

single.php

<?php while ( have_posts() ) : the_post(); ?>

	<?php
	
	if (get_post_type() == 'salesbinder_item')
		get_template_part( 'content', get_post_type() );
	else
		get_template_part( 'content', get_post_format() );
	
	?>

archive.php:

<?php
/* Start the Loop */
while ( have_posts() ) : the_post();

	if (get_post_type() == 'salesbinder_item')
		get_template_part( 'content', get_post_type() );
	else
		get_template_part( 'content', get_post_format() );

endwhile;