Deleting a Source through the Console deletes all entry points to that Source from the Console. The backup files are not deleted, however, so the way to access the .bak files for the Source is to add the Source to the Application again. The backups will be available through the Backup/Restore tab once the Source is relinked to the Application. Previous settings will be restored to the Source once the Restore process is done. (Please note that your restore is successful even though there is no on-screen confirmation.)