To add to that, I want to point out two thing:
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BookBrainz uses a copy of the country/region/city database as MusicBrainz, although it must be out of date currently and in need of a refresh.
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Regions and cities are indeed in the BB database, but currently not accessible due to an issue processing such a huge list of entries. Having cities available could help solve some of the problem at hand: a country of birth might no longer exists while a city of birth could remain unchanged.