Thanks for your suggestions. This is more or less what I was afraid the turnout would be.
Though I really cannot see how the disc that plays with that significant distortions can be ripped or copied to give better results on the disc the files are copied to.
In fact I had already tried to copy one of the affected CD-Rs via my CD burner but the burner refused to continue after the first reading step.
The sound distortion is hard to describe but is just what it was on the occasional CD-R that had failed in the past (after a couple of years). Except that on those older CD-Rs the sound got worse towards the final tracks (indicating that data had started to fail from the outer edge towards the center) . Whereas with the CD-Rs I recently got and turned out to be bad, the sound improved towards the final tracks (without getting perfect), which to me seems to indicate that the center area where the label clearly had started to peel was affected more because the CD rotates faster when the laser reads the music data in that zone and slower as it advances towards the outer edge.
On one CD-R (that I found a bit more important to salvage, though it is no desert island CD either ) I tried to remove the label manually but it was only the already detached section that came off (both round the center hole and near the edges). But that neither improved nor worsened the playback sound.
So I guess I'll at least try to make "next-generation" CD-R copies of those that are still intact. In preparation of other CD-Rs that might come my way from that source and that might be historically more important to safeguard for the future. (Different story ... )
More details? Hand-printed sleeves, sealed, open, condition, what the sleeves look like?I know I can do this myself, but would you be willing to at least post pictures of the album sleeves? The atcual albums?