O.S.Bates aka Oz Bates Movie Poster artist
O.S Bates was a cartoonist and illustrator in Australia in the 1950s and 60s. He was also known as Oz Bates. He produced the art for some ads in newspapers including the Sunday Telegraph in 1968. The signature on the daybills in this gallery are the only examples of his work on movie posters but it is likely that he designed other movie posters during the 1950s. The poster that bears his signature is a "stock" daybill used for re relase screenings of various films. The cinema owner could add the screening details in the blank space.
It is strange that Oz Bates signed a fairly obscure "stock" daybill but the majority of Australian posters were usually unsigned so it is very difficult to determine how many other posters he might have designed. If anyone has more information on Oz Bates please let me know.