Original 1st printing 14&1/8 x 20" concert poster for Quicksilver Messenger Service appearing along with the Sons of Champlin and Blackburn & Snow at the Avalon Ballroom in San Francisco, CA on 10/28-29/1966. Art by Victor Moscoso, image ("Chicken on a Unicycle") is # 32 in the Family Dog/Avalon series. Medium-thick flat vellum stock poster is in good to very good (B to B/B+) condition; a 3&1/2 x 1/2" streak of discoloration along the lower right margin (likely beverage stain), light handling, a few stray age spots, a tiny edge nick or two and a sliver of vertical creasing along the upper left margin, otherwise fine. An overall wonderful-looking example of this very early Moscoso poster from the Family Dog.