Why would the plane go from Scotland to Vancouver on the west coast? A plane from Scotland would have landed on the east coast, especially in 1961.
Polar route.
Over the pole route?
That was the route for planes coming from Kenya at the time, it landed in Vancouver, B.C. with perhaps a stopover in Gander Newfoundland.(to refuel) The route is listed on the extremely long 6,800+ thread which started back on July 3,2008.
Probably, if so it would have stopped in Gander, Newfoundland Canada, many US military flights moving troops to and from the sandbox/rockpile stop there to refuel even today. But if the destination was Hawaii, they would not go through a US east Coast city because they are too far south of the shortest (great circle) path from Scotland/England, even Gander is somewhat south of the path.
I looked at a great circle course calculator, and while Kenya to Britain, to Newfoundland to Vancouver to Hawaii is longer than Kenya to Hawaii, the direct path goes over China (not friendly in'61) and probably had fewer routes available. The route via London would have had more flights, and probably some stops along the way, either in North Africa or Italy. Flying from England to Hawaii via Gander Newfoundland and Vancouver/Seattle would be longer than direct from Great Britain to Vancouver/Seattle and then to Hawaii, but may have been too far for most or all commercial aircraft in '61. Thus the most probable path from Kenya to Hawaii would be through London, Gander, Vancouver or Seattle, and then on to Hawaii, with another possible refueling stop somewhere near Italy.
The fact that the world (almost) round can be confusing when thinking of flat maps.