Original 1939-41 GMC Truck Dealer Parts Book. This Book of Parts covers the Models AC & AF 500 thru 850 H/D Models. This is what the Dealer used to order Factory Replacement Parts to Repair your Truck. It has Part Numbers, Description, Quantity, Application and some Illustrations. This vintage Book is in good condition for its age with normal wear, soiling and blemishing from use in a Dealership [see photos]. Very rare and informative piece of history that will be a geat and useful addition to any GMC Owner or Collector.