I just saw they do offer flights from Scotland to Vancouver with a stop in Calgary. That would make sense.
From I have just tried to learn, they only started doing commercial polar flights late last century.
Well, yes and no. They did the best they could, but most airplanes then did not have the range to fly a true great circle (polar) route from London to Calgary, Vancouver or Seattle. Thus they would have an intermediate stop in Gander Newfoundland to refuel, take on more food and drink, and empty the wastewater holding tanks.