I was never at Expo 58, as I was all of six years old at the time. My aunt did go, though, and later gave me her guide book, pictures and an 8mm film she took. She never quite figured out how to hold the camera, and many of her shots show her thumb blocking the shot. We have movies of her thumb at a bull fight, her thumb in Rome, etc. I was really impressed with those films, though, as they were my first look at a world's fair. I've also had a special fondness for Expo 58 since then.
Here's a view of the interior of the USSR Pavilion. The Cold War was well under way and the USA and USSR were both determined to out do each other. I have to say that this was one impressive looking pavilion indeed.