1928 Professional Baseball Leagues Convention Attendees Credential Pin Toronto1928 attendees credential pin for the National Association of Professional Baseball Leagues Convention in Toronto, Ontario, with pin backed rectangular segment Pin reads "The National Assn Professional Baseball Leagues 1928 Convention" in raised lettering on a baseball motif Stamped on back with "M. Rosenthal, Toronto" Rectangular segment sits above with a green, yellow, and red enamel maple leaf and slot where an attendee's name could be inserted The