Letters credit for cover confirmed by Todd Klein via files of Danny Crespi (as posted to Facebook through the Comics Historian Exchange page, 16 August 2016). Originally credited tentatively to "Annette Kawecki ?"
Letters from Ken Meyer Jr., Demetrios Frangos, Edward B. Via, Larry Grossman. Includes a house ad for the Incredible Hulk # 181 and Marvel Value Stamp # 6 (Thor).