Here's a scan showing a number of baseball cereal premiums from the 1930s.
Pictured (clockwise) are the 1939 Baseball Centennial Pencil and mailer from Wheaties/Jack Armstrong; the 1933 Wheaties Babe Ruth Flip Book; the 1935 Quaker Babe Ruth Champions brass club badge; the 1934 Quaker Babe Ruth Baseball Club Cello button; the 1935 Quaker Babe Ruth Champions Cello button; the 1936 Grape-Nuts Dizzy Dean Winners Club bust membership pin; the 1936 Grape-Nuts Winners Club ring; the 1935 Grape-Nuts Winners Club bat membership pin; the 1935 Grape-Nuts Winners Club ring; the 1937 Post Huskies Club ring; the 1937 Post Huskies Club membership pin; the 1935 Grape-Nuts Dizzy Dean Winners Club Good Luck Coin; the 1939 Quaker Baseball Centennial Baseball Scorer Fob; the 1935 Quaker Babe Ruth Baseball Scorer Fob (with Boston Cap); the 1934 Quaker Babe Ruth Baseball Scorer Fob and Strap (with Yankees Cap); and the 1935 Quaker Babe Ruth Big Book of Baseball.