I'm unable to find anything that resembles a catalog number on the other discs. The PC Gamer version does have
122 MT v3.6 MTC000408 written on the right side, but I'm not sure that's any kind of catalog number (though to be honest I have a pretty conservative view of what a catalog number is). But perhaps the other pictures should be moved to
the entry with no catalog number? Then they're all at least in an entry that has the same (non)catalog number, rather than in an entry that has a unique one.
Err, on second thought, I don't know what's going on with that entry. It has different track times, and there seems to have been some discussion about it. There's no picture of the disc and it's called the European version, so it's a really confusing factor. I'm not sure what to do.