msycamore said:

So we might perhaps start to refer to these versions as the Stereo and Mono versions.

Actually, on a second thought it's probably better to refer to this as an opening day vs. wider release variation, sort of like what happened with Empire that had modifications seen a month into its run when it was time for the 35mm versions. As Dolby Stereo prints have these modifications as well, it only gets confusing. ;)

The most likely scenario on the info we have is:

May '77 - Dolby Stereo prints - containing the rare credit roll and cloudy composite, possibly an early more unstable composite of the opening crawl.

June '77 - Wide release with a third Academy Mono mix for a large number of prints, with the above shortcomings corrected from then on.