Nice classic trenchcoat.
I'm not sure when they were manufacturing in Canada, but they received the Royal Warrant for the Queen Mother in '52 and the label is very close to the design used in the late '60s-early '70s so you have a ballpark.
There should be some more labels: fabric, even care perhaps? Styles like this can be hard to date as they're not prone to the vagaries of fashion and Aquascutum specialised in trench coats. Construction details too, if you can provide eg, are there any shoulder pads, how are the seams finished? My feeling is '60s but additional information can help.