He originally bought the 3 and 5 liter. The sizes are impressed to the underside of the handle pre firing. (Handle lug) The three pieces we have are noted here: The. 5 LITER: 510A5B5LITER 3LITER: 5A3B3LITER21 2 LITER: A2B2LITER The cover has the label: PYREX A12CB please look at pictures.Dow Chemical and Corning Glass formed Dow Corning. These early pieces were available at the Dow Store for employees along with other products produced by Dow and it's affiliates. I have seen some of the earlier pieces fetch some very high prices but have not seen any of the early rare handle lug marked pieces. Thanks for considering this item. I have put a price illustrative of other similar pieces but feel free to make an offer. Thanks and have a great day! The item "Vintage Corning Ware Blue Cornflower Set of 3 very early markings on handle lug" is in sale since Sunday, January 24, 2021. This item is in the category "Pottery & Glass\Glass\Glassware\Kitchen Glassware\Corning Ware, Corelle". The seller is "rkinnun" and is located in Midland, Michigan. This item can be shipped to United States.