How to fix lost Paperclip asset pictures, because asset_file_name wasn't successfully saved

paperclip.rake

namespace :paperclip do
  # Fix broken timestamps
  task :fix => :environment do
    # All user picture files in the production environment (directories[1])
    files = User.last.picture.send(:connection).directories[Rails.env.staging? ? 2 : 1].files.select do |file| 
      file.key.starts_with?('users/pictures')
    end.sort_by(&:last_modified)

    (0..300).each do |ranged|
      puts "Ranged: #{ranged}"

      Paperclip.each_instance_with_attachment('User', :picture) do |instance|
      # User.find_by_nickname('Cyn').tap do |instance| # Run only one person

        begin
          puts instance

          files.each do |file|
            # This shouldn't be called because of our select block above
            # but, well...
            next unless file.key.starts_with?('users/pictures')

            [ranged, -ranged].each do |difference|
              instance.picture_updated_at = file.last_modified + difference.seconds

              if file.key.include?(instance.picture.hash_key)
                p [instance.name, instance.nickname, instance.id, file.last_modified, file.key, '...']
                puts instance.picture.url

                instance.update_column :picture_updated_at, instance.picture_updated_at
              end
            end
          end
        rescue => e
          puts [e.class.name, e.message, *e.backtrace].join "\n"
        end
      end
    end
  end
end