If it's marked the Anti Reflective coating, you're stuffed (sorry not to sugar coat it). The more you try and polish out the mark, the more it will strip off the coating, the worse it will look..
However, i have a spare 32" RF contrast screen we kept for an emergency but haven't needed in 2 years. You're welcome to borrow it on a permanent basis if you like.. Doddle to fit too - swaps over in minutes!!
Lee
BeoWorld - Everything Bang & Olufsen