Dennis -Besides Hugo Díaz, there's newer music to check out, even though tango, chacareras, zamba (not with initial 's') are not "latin" as caribbean music.
For Brasilian, check out Rildo Hora and Mauricio Einhorn.
For Argentinian (both tango and rural styles) check out the inimitable Hugo Diaz (the harmonica player, not the bandoneon player of the same name). Also, Angel Villoldo, one of the fathers of tango, was said to play the harmonica. But while he recorded some 78s as a singer and monologuist nearly a century, I've never found any recordings of his harmonica playing.
Fernando Toral Argentina