Depending on the depth of the scratch it may be possible to restore it.
Because the cathode ray tube has an internal vacuum, the thickness of the tube face cannot be polished below a certain critical depth, as it must withstand the air pressure acting against it.
Take it to a reputable TV service centre and ask their opinion. If they think it's possible to polish it out, they can arrange to remove the tube and send it away for professional polishing.
It won't be cheap, due to shipping costs of a heavy item plus the polishing but it will be less expensive than replacing the tube completely.
Cobweb, October 2004
