I have some 10 year old Kodak Picture CDs. One of my drives recently had problems reading one of them, so I did some scans with a different drive. They all have C2 errors, but the TRTs seem weird - they all have a gap near or at the end, but they didn’t fail.
I attached a couple of the TRTs, and one of the DQs. Fortunately I was able to use the other drive to copy all the data off the discs.
Looks like the disk may have gotten damaged or gone bad from age. I have a few burned disks that have small missing areas of the writing surface that you can see though from getting scratched and what not. Regular cd’s can do the same thing with enough damage as the data layer is on the top under the printed label as far as I remember. If there’s any data at those points it’s gone for good.
IF the disk is just scratched badly enough for the laser to not pickup the data that is still there you can polish the disk if they are small and you might be able to read the original better again.