Star Wars: The Empire Strikes Back (partially found 70mm print of sci-fi film; 1980)
The original theatrical versions of Star Wars are rather difficult to find, but are still doable with enough effort; this version, on the other hand, is a much different story. When The Empire Strikes Back was first released, it was released in two variants -- the 35mm print and the 70mm print. The 70mm print, according to Wikipedia, was released in 126 theaters first before a much wider release that was predominantly the 35mm print. The 35mm version is, by far, the much more well known one, and in fact, it was the basis of all the home video releases prior to the Special Editions, and even past that, the SEs onward still take much of their basis from it with a few exceptions. The 70mm print, on the other hand, has never been found in its entirety. It contains a numerous amount of audio and video differences from the far more widely seen print, including some changes in scene transitions, some altered dialogue (including Luke's "You were lucky to get out of there" instead of "You're lucky you don't taste very good", a change that is often misattributed to the Special Edition), among other things. Much of the information provided on the differences was given by Michael Matessino in an issue of Film Score Monthly, who claimed to have seen the movie 70 times when it originally came out.
In February 2011, Originaltrilogy.com user morgands1 uploaded a full audio recording of an original theatrical showing of the 70mm version. While the audio quality has deteriorated a tad and it isn't stereo all the way throughout (one of the tapes has been lost), and of course has the problem of being an external recording so ambient noise is still heard, it still is a major part of the puzzle and still provides access to all the audio differences and in fact confirms them. Additionally, there exists a five-second recording on YouTube of this version as well, though doesn't exactly give away much. Some Super8 reels seem to be based off this version as well. However, the print in its entirety still has yet to fully surface.
- Bootleg audio recordings of the original 70mm version. Retrieved 26 Dec '17