Searches WordPress media library for unattached media, tries to locate the post where it's used and attach the media.
Place the folder in wp-content
Use WP-CLI to run it with: wp eval-file wp_media_attacher.php --debug and to save all output to log file wp eval-file wp_media_attacher.php --debug > doit.log 2>&1
Not nearly production quality. Used to clean my own really old (20+ years) websites.