In late October 1971, a potential customer for one of the Herrick covers wrote to NASA to inquire about its authenticity. On November 5, Slayton responded, saying NASA could not confirm whether it was genuine. He warned Worden to ensure that his covers would not be further commercialized. Worden wrote an angry letter to Herrick. In June 1972, Herrick instructed Siegel to send 60 covers to Worden in Houston, which he did by registered mail. Until this point, Siegel had assumed the 60 covers belonged to Herrick.