1948, Amateur World Series Issue, specialized collection in two binders, arranged by denomination, including trial color proofs with Waterlow overprints, the issued souvenir sheets with manuscript "File Copy", "Muestra" overprints, imperforate proof sheets, as well as on-cover uses (mostly philatelic), generally very fine, many of these items only exist in extremely limited quantities (for the imperforate sheets as few as three are in private hands), an extraordinary opportunity for the baseball or sports topical collector
