I have come across this issue. Whilst specific albums / tracks may not be available for sale in the iTunes Store of your country, Apple has them on their servers and are probably available in other countries - they may have the rights to offer them as downloads.
By the way, clicking on Find in Store is not a guarantee that the track has been matched with that track!! Whilst the match process does not use metadata for matching, it appears that it uses the metadata when using find in store function.
I have had songs match with limited metadata and was not able to find in store.
Thanks! It's just confusing when I don't see it anywhere in the store. I am also having the same issue with another album that makes sense with what you said. This other is a girl from England, and it's not on the US store, but I'm guessing it's on the UK iTunes. I will play around with it and see what results I get. I may purposly convert to a low bitrate, and change the metadata just to see what it does when I match them.
Thanks for the reply!