'Set in a futuristic view of the late 1980s' ....
... according to the iMDB synopsis, yet really there's hardly any indication whatsoever the movie was supposed to be set (roughly) 20 years ahead of its actual release date.
The planes the characters ride on don't look particularly advanced, the TV sets and telephones the characters use don't look futuristic. On the street scenes set in the streets of Rome, everybody is driving mid-1960s cars.
The big video display screen Premier Olivier uses to display the film clips to Bishop Kiril I guess probably was pretty advanced for 1968, but certainly the Premier of the USSR would have been privy to state-of-the-art home theater equipment.
I think the only real indication this all was supposed to be taking place in the future was that Kiril was supposed to have been sent to the Gulag roughly at the time the movie was made (1968) and released "almost twenty years later."
So even though in theory "SOTFM" was supposed to be set in 1986-88 or thereabouts, there really was no indication in the movie itself it didn't take place in 1968.
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4) You ever seen Superman $#$# his pants? Case closed.