I wouldn't add anymore insult to the forged glass. I've seen a Loetz vase that had a signature scratched out (probably LCT) and it looked so bad. I think sellers should just report the forgery "scratches" like any other damage and hope that the glass doesn't show up on eBay. Really, we can't control what happens to glass after it leaves our hands. We can only hope that things fall -- I mean, land gently -- into honest hands.
Anita