Canadacan, take a look at the side panel of the crate. Right above the word Beverages is the date stamp. It is 11/47.
So I would guess this means the double dot was around Canada in 1947.
embe thanks for sharing! So I'm seeing your bottle is from Dominion glass, with a 9 for 1949 and a month code F for Nov/Dec, we now have 8oz, 10oz DD from 1949.Better late than never, here's what the bottom of mine looks like. Quebec also according to the label