it may not even be the scratches.
its a 10 year old disc - a lot of discs start to degrade by then, especially non-premium media stored in less than ideal conditions (filed vertically, in a dark cool place).

try reading them in several different drives - preferably DVD burners. you might luck out.

if you have any other backup CDs/DVDs that are from the same period, you may want to back those up as well while you can. also, when writing CDs/DVDs, dont try and squeeze on every last meg of data onto them or overburn -- they generally start to degrade from the outside edge.