I remember reading some discussions over the opening Fox logo. It would seem that there are slight differences between some of the logos, so taking the logo from a movie of the same time period may not be 100% accurate, but I guess it'd be good enough.

Alien would probably be a good pick. Aliens in 1.85 though, so it's the wrong aspect ratio.

Looking at the logo at the start of Alien, it's a bit different from the Star Wars & ESB ones. The 20th Century Fox thing is a bit on the left (as opposed to centered), there's some difference in the spotlights, and the blue isn't as dark.