Second version of the Office 2008 converter script

Well Steve Maser asked me to come up with a version that would work recursively on all files inside a folder you would drag to the script.
He also suggested that I added the W6BN type (for Word 6/95 files).
So I based the script on one of the examples provided by Apple, and here is the result:

-- This droplet processes files dropped onto the applet
on open these_items
   repeat with i from 1 to the count of these_items
      set this_item to item i of these_items
      set the item_info to info for this_item
      if folder of the item_info is true then
         process_folder(this_item)
      else
         tell application "Finder"
            
            -- get the file type
            set TheFileType to file type of this_item
            set UpdatedFileType to TheFileType
            
            -- detect old file types for Office files chose the correct one instead
            if TheFileType = "WDBN" then set UpdatedFileType to "W8BN"
            if TheFileType = "W6BN" then set UpdatedFileType to "W8BN"
            if TheFileType = "XLS4" then set UpdatedFileType to "XLS8"
            --   if TheFileType = "SLD8" then set UpdatedFileType to "SLD8"
            
            -- set the new file type
            set file type of this_item to UpdatedFileType
         end tell
      end if
   end repeat
end open
-- Just in case people try to open the script through a double-click in the Finder.
on run
   display dialog "Drop your files or folders to be converted on this icon"
end run

-- this sub-routine processes folders
on process_folder(this_folder)
   set these_items to list folder this_folder without invisibles
   repeat with i from 1 to the count of these_items
      set this_item to alias ((this_folder as Unicode text) & (item i of these_items))
      set the item_info to info for this_item
      if folder of the item_info is true then
         process_folder(this_item)
      else
         tell application "Finder"
            
            -- get the file type
            set TheFileType to file type of this_item
            set UpdatedFileType to TheFileType
            
            -- detect old file types for Office files chose the correct one instead
            if TheFileType = "WDBN" then set UpdatedFileType to "W8BN"
            if TheFileType = "W6BN" then set UpdatedFileType to "W8BN"
            if TheFileType = "XLS4" then set UpdatedFileType to "XLS8"
            --   if TheFileType = "SLD8" then set UpdatedFileType to "SLD8"
            
            -- set the new file type
            set file type of this_item to UpdatedFileType
         end tell
      end if
   end repeat
end process_folder

The compiled script is here and again, please make tests only on a copy of your files.
Feedbacks are much welcome.