https://bitslog.com/2013/09/03/new-mystery-about-satoshi/

'The selected set of bytes (0 to 9, 19 to 58) could have been selected to map a somewhat extended alphabet into this set. This must be explored further.
Another idea that crossed my mind is that the set itself has a kind of hidden message... I hope my friend Timo (the mathematician) now finds the hidden message and brings me some peace.'


Base58 isn't appropriate for text messages. Bitcoin uses Base58 for WIF publickeys and privatekeys.