1) You can buy a CD polisher which will work (I have used them) providing the scratches aren't too deep. The system I have uses water as a lubricant and it is OK.

2) You can get a liquid polymer (filler) as part of a kit which also needs to be polished on and off to a CD. I haven’t used this kit but you used to be able to find them in HMV or Virgin records.

3) you may want to see if you can copy the CD with a PC. It may work and hell, you have already paid the industry there due !