Yes, this expression is also from Iceberg Slim's book "Pimp - The story of my life". (Just like my former questions) The author is a black man, who was pimping in Chicago in the 30s but later squared up and wrote books about his experiences. When he got into jail for the second time he writes:
"This was a prison of cliques, of bloody vendettas. I found my level with the soft spoken, smooth, Midwestern pimps and stuff players”
My sixth sense whispers that "stuff player" means some kind of a con man here, but I am not sure....