Jack Kirby appears to have redrawn much of the background figures including Hawkeye, Scarlet Witch and the Sons of the Serpent. Info per Nick Caputo, August 2012.
Letters from John Kusske Jr., Jimmy Sartoris Jr., Rudy Espinosa, Bob Barnett, Gary Robinson, Thomas L. Chaffee, and Peter von Sholly; includes M.M.M.S. membership form, and illustrations from Tales of Suspense (Marvel, 1959 series) #82, page 4, 4th panel (Captain America), The Avengers (Marvel, 1963 series) #31, page 4, 3rd panel (Goliath), #30, page 19, 5th panel (Hawkeye and Black Widow).