The reason I earmarked Kodak was because in the 50s, 60s, even 70s, they were the dominant force. They were truly ubiquitous, not merely another player, like today.
They were dominant in the North American market. I suspect that Agfa was at least as important in Europe. and Fuji, Sakura/Konica, and Mitsubishi were about the only brands you might find in Japan. Not to mention all the smaller players in various places. I would guess that in the late 40s and 50s you would have a hard time finding anything OTHER than Ferrania In Italy for example.