Parsing UTF when converting localhost URLs to paths

I can get a localhost URL of an open file in Preview using

tell application "System Events"
	tell process "Preview" to set thefile to value of attribute "AXDocument" of window 1
end tell

However, if the path contains a bullet or other high-ASCII character, the result may look like:

How can I convert that string to a file path including the bullet (“¢”)? I need a string that looks like this:

on urlToPOSIXPath(theURL)
   return do shell script "python -c \"import urllib, urlparse, sys; print urllib.unquote(urlparse.urlparse(sys.argv[1])[2])\" " & quoted form of theURL
end urlToPOSIXPath

on urlToPOSIXFile(theURL)
   return POSIX file urlToPOSIXPath(theURL)
end urlToPOSIXFile

urlToPOSIXFile("file://localhost/Users/scb/%E2%80%A2folder/proposal.pdf") as Unicode text