I have found that there is a tool to actually fix those scratches. After using fine grit sandpaper 1500 and rubbing and attempting to polish these older cd's of mine to work, I finally broke down and found that there is a toool called the disc Doctor. For cd's as well as dvd's. You place th ecd in a holder and as you turn the crank handle it runs a fine grit of sandpaper under the base of the cd removing the cd scratches. Note it will put a high swirl scratch on teh cd just as if you were waxing a car in a rotational pattern, but it does work. Used this on audio cd, data as well as playstation after the kids had got a whole of them and put a few deep scratches in them. they cost about $24 dollars and can order them online as well as most music stores now carry them here. also are available at Radio Shack.
Rob