An extra couple of snippets from the In70mm site:
Some engagements added 70mm blow-up version of animated short "Duck Dodgers In The 24th And A Half Century".
(From this page.)
"Sorcerer" film editor Bud Smith recalled his experience in seeing the coming attractions trailer he had cut for that film in front of "Star Wars" at the Chinese Theatre: "When our trailer faded to black, the curtains closed and opened again, and they kept opening and opening, and you started feeling this huge thing coming over your shoulder overwhelming you, and heard this noise, and you went right off into space. It made our film look like this little, amateurish piece of [expletive]. I told Billy [Friedkin], 'We're [expletive] being blown off the screen. You gotta go see this."
(From this page.)