A few comments about upper berths.
As to windows, most open section sleepers did not have windows by the uppers, but there were a few that did, such as the Illinois Terminal’s sleepers, and the lightweight sleepers built with sections for the Overland Route trains before WWII. Indeed, the first time I slept in an upper I was able to look out in the morning before I got down (if you had an upper, you got down to get up), for the IC was using pre-war 6-6-4 sleepers on the Seminole at the time (my car was American Sailor, which was in the consist of the first daily City of Portland to leave Chicago). Now, if you sleep in an upper in a Viewliner, you have two windows.
One disadvantage of the upper, until after WWII, was that you had to call the porter for a ladder if you were going up or coming down; some time after the war the folding ladder, which was attached to the upper, was developed, and it was no longer necessary to call the porter. As I remember, these were found in new lightweight sleepers only, I am not certain that pre-war built lightweights were so modified (I really do not remember if American Sailor had the individual ladders).
One advantage of the upper was that the foundation of the berth was solid, and not composed of four pieces, as the foundation of the lower was.
The June, 1971, issue of the Guide is the last issue I have in which the CN and the CP mention the sleeping accommodations available. By then, the CP was using only cars that had been built for the Canadian, but the CN was still using cars with open sections, of different ages, on all but one of its trains that were operated with sleepers.
Perhaps it was felt that the cars built by Budd for the Canadian were superior to the other cars, and the other cars were removed from service. Then, when it seemed that more cars were necessary for the Halifax service, VIA bought the car shells and provided bedrooms in th