Untitled photographic flip book

Baltimore, Maryland : Flag Studios, [between 1970 and 1975]. Oblong octavo, suede covered boards bound with metal studs, the upper covers opening at the centre, containing four “flip book” series of 12 photographic prints (48 in total), each 55 x 75 mm, being the upper or lower parts of male heads which can be matched in various permutations to make composite portraits; on two further “pages” are the publisher’s undated imprint and the names of the creators with their printed signatures: “Karl Aido (?) in collaboration with David S. Simpson”; in good condition. An obscure, whimsical artists’ book.