I would take the best possible photo of it before you start scraping. Set your camera at its highest resolution and get close enough that the sticker takes up the whole photo to make sure it is easily readable.
That may be the last time you see it intact, once you start scraping.
If it won't scrape out, I would even consider replacing the glass with a junkyard piece, and storing that one in the attic. That is probably a little extreme for most folks, though.
Slonaker