The deaf and dumb con artists portrayed in the 1850 newspaper item below prefigure the stranger with the slate at the beginning of The Confidence-Man (1857). Besides that, the story offers credible evidence (previously unknown?) that Melville actually met Simms in person, more than once.
From the Charleston [South Carolina] Courier, Thursday, May 2, 1850:
The Melvilles.—Two persons visited our town lately, under the above cognomen, one of whom represented himself to be Herman Melville, the destingished [sic] author of “Typee,” “Omou’ [sic], and “White Jacket.” They exhibited some beautiful specimens of penmanship, and expressed a desire to teach a class that useful art. They pretended to be deaf and dumb, which raised a suspicion in the minds of some, that they were not what they pretended to be. This suspicion caused a letter to be addressed to W. G. Sim[m]s, in reply to which, that gentleman says that he has, on several occasions, met Herman Melville, the author, and that he was in the full enjoyment of all his faculties, in as high a degree as any other person. Before the receipt of this letter, however, the Melvilles had sloped in the Northern stage.—Cheraw Gazette, 30th ult.