Maybe a bit out of topic, cause I'll mention resorts instead of pavilions, but I found interesting to mention an old book I had in my old boxes, just dusted off, it's called A Complete Edition about Walt Disney World, The Vacation Kingdom of the world.

It's a thin 20 pages book from 1969, with a message of Roy Disney. It just mention EPCOT with no detail, but what I found interesting (and about countries) is that the initial idea of resorts include 5: Polynesian, Contemporary, Persian, Asian and Venetian, with coloured pics of the models.