Production to Development migration

I am new to a company and the previous Web Developer up and left without any hand-off of information. I have a small website with both a Development site and a Production site. Both sites are nearly identical minus a few updates on the development site. I would like to bring my Production site into development to test the updates I have made in development as well as upgrade the site and plugins to the new WP 4.0 but I am having trouble getting the Production site into Development and maintaining the sites integrity at the same time.

The web server is SUSE Linux with Apache, PHP and MySQL

Steps I am taking to bring Production into Development:
-Backup Dev and Prod WP directories (tar)
-Dump Dev and Prod MySQL databases
-Extract Prod.tar into my home dir
-Edit wp-config.php to change the DB from Prod to Dev
-Edit the Prod SQL dump reflecting URL changes from Prod to Dev site.
-Restore the Dev DB with the edited version

—Everything works on the Development site at this point.

-Move the current Development WP files into a Backup directory
– rsync the extracted Production files into the now empty Development directory

Upon moving the Dev environment and placing the Production environment into Development, the site still works and the theme stays intact but none of the images show on the site. This includes buttons, special drop down windows, etc. Also, all of the plugin images (such as the icons next to the plugin names in the admin window) are all not loading as well. All links go to the Production site as well instead of the Development sub-domain, even after updating all of the Database values to reflect the sub-domain.