If Jack Dempsey is the guy that Mike Tyson wanted to be, then Sam Langford is the guy that Jack Dempey wanted to be. Later in life when Langford was blind, Dempsey paid a lot of his bills.
Clay Moyle talks about it in an article on CBZ: Among the 705 contributors were men fighters Jack Dempsey, Beau Jack, Fritzie Zivic, and Joe Louis, and boxing promoter Mike Jacobs
If Lennox Lewis was fighting to the Wills schedule he would probably drop a couple to a peaking Langford, like Wills did. But in isolation they will beat him every time. I don't think that Langford is a serious pick over Lewis in a fantasy match up, for example.