correcting scratched glass?
 

This happened to my car windshield when I overdid it with a Scotch Brite pad
trying to get off some crazy glue that a vandel squirted on it. I called
every car window place in town and no one could fix it. If it can't be
buffed out on a windshield where you can get to it easily, I doubt anything
can be done about your portlight.

--
Roger Long