When you insert the CD containing the second recording click No when you get this prompt:
Then select all the tracks on the CD (Ctrl-A on the keyboard), right-click > Get Info and modify the properties shown on the Details tab so that the combination of Artist and Album (or, if the CD contains tracks by different artists - i.e., orchestra/conductor/soloist combinations - Album Artist and Album) are different from those of the existing recording in your library. So, in this example, iTunes will keep these as separate albums because the Artist value is different even though Composer and Album values are the same.
Now you can import the CD. should not get a warning about over-writing existing tracks, and will end up with separate albums in iTunes.
The underlying problem is the lack of quality control with the Gracenote service that iTunes uses to look up the details of CDs before importing. For example, when I insert the CD for the first of the two recordings illustrated above I get four choices:
This is presumably due to Deutche Grammophon's repackaging of the same recording as part of multi-disc sets, but I'm pretty sure that the first and last shown here are the same disc in the same box set. Likewise, since anyone can submit CD details to Gracenote you may have completely different recordings being submitted with the same info, especially if the people entering the details put the composer information into the Artist field.