Vintage range from 1930s to 1960s. The smaller jugs have DP marking on the bottom which stands for Dominion Products.  Canada's largest flass manufacturer.  The 80 on the bottom of the smaller jugs stands for 80 ounce.  The 3 and  7 represent mould cavity number used by the factory line to track exactly which machine mold pressed the glass.  The larger jug does not have any visible markings.