Did everyone in the cryptography mailing list always use 's' instead of 'z', though? "Satoshi" is quoting Hal Finney here, and Finney was American...

Is anyone familiar with either of these email addresses being known to have been used by Satoshi? If so, why the change? 

Also, nostr:npub1z4m7gkva6yxgvdyclc7zp0vz4ta0s2d9jh8g83w03tp5vdf3kzdsxana6p, what is your source for these documents?