Molly said:

So I take it the majority of the differences are rearrangement of scenes, and not added or deleted footage?

I'm not familiar with THX, I'm mainly curious and from a preservation standpoint.

Between 1971 and 1978 yes, it would seem so. And those changes all (if I recall) occur in the second half of the film, after the arrest. The exception (footage not present at all in the 1978 cut) being about 30 seconds of the SEN + kids scene, which was almost certainly removed due to bad child acting and really bad voice dubs.

I'll have my "Unspecialized" reconstruction on spleen sometime tonight if anyone is interested. It would be up, but my computer crashed mysteriously during the encode.