a minor question from me as well.
Who is to say the label wasn't used after the exhibition? Was there a rule about who used the stickers? Did someone go round and specially stick them on the items in the expo pavilion, or... were each company allowed to use the stickers on their items thereafter, to denote they'd exhibited at the Expo 58?
It was 1958 - and, it is claimed, someone stole the Sputnik facsimile after all -so rules may not be rules.
Russia appears to have 'folded up' their pavilion and taken it home with them

Amazing feat of engineering that.
From Wikipedia
'The USSR[edit]
The Soviet pavilion was a large impressive building which they folded up and took back to Russia when Expo 58 ended. They had a facsimile of Sputnik which mysteriously disappeared, and they accused the US of stealing it[citation needed]. They had a bookstore selling science and technology books in English and other languages published by the Moscow Press. On the exposition there was also a model of Lenin first nuclear icebreaker, and cars: GAZ-21 Volga, GAZ-13 Chaika, ZIL-111, Moskvitch 407 and 423, trucks GAZ-53 and MAZ-525.[8] The Soviet exposition was awarded with a Grand Prix.[8]'