I have seen 431-18 for Curry, but remember he was a pro at 19... Bernard Taylor was allegedly 481-8 Kelcie Banks had 505 fights I suspect Lazlo Papp and Stevenson would be up there as well.
Mark breland was ca. 119-1, winning 5 golden gloves titles (ny) SRR was ca. 75-0 beating Pep and Billy Graham along the way
Looking this up, the numbers need to be taken with a pinch of salt: Lazlo Papp: http://www.geocities.com/pedrinet/papp 1968 Gold Medallist Francisco Morochito Rodriquez had a record of 266-4 Dave Hilton Jr 130-2 Matthew Hilton 106-0 Alex Hilton 101-1 Benvenuti 119-1 Napoles 113-1 Brleland 110-1 Courage Tshabalala 83-1 Harry Mallin claimed an unbeaten Amateur resume of over 300 fights Joan Guzman 312-10 Felix Savon 387-21 Mario Kindelan 358-22 Teofilo Stevenson 302-22 But the Daddy has be Dick McTaggart 610-24 with an Olympic Gold, a Val Barker and 5 ABA Championships to his name.
History contains a lot of myths. This undefeated record is one of such myths. And he only fought local opposition, not world class.
But there is no evidence brought to the table on this forum to prove he lost. And the local talent is from the New York area which generally is not to bad.
I would trust the head of IBRO over Bob Mee any day of the week. The info he got originates in New York Daily News newspaper that founded the NY Golden Gloves tournament. Here is a list of all NY GG champions over the years: Pesca who beat Robby won the tournament in that category.