A) Wasn't the 70mm basically the same as the stereo?

B) Wasn't there stereo showing on opening day, not just 70mm?

Looking here http://www.in70mm.com/news/2003/star_wars/index.htm it seems there were only 8 engagements of 70mm at first, so the film did not start out exclusively in 70mm and presumably also started in 35mm. They say it's mistaken to think that the film started exclusively in 70mm and only went to 35mm weeks later. But they also seem to think it's not true that the opening was exclusively dolby stereo (70mm and 35mm), which implies they think the mono was part of opening too. I don't know where they get that, because what I've heard is that the mono was still being worked on (recorded) on opening day and wasn't released until sometime in the summer. I think it was zombie84 who spoke of anecdotal evidence of Lucas still recording the mono when the film opened. if they could be wrong about that, could they be wrong about the other thing? Surely if there were only 8 70mm opening engagements then there had to be more to the opening than 70mm.

Also, it's my impression that there weren't any pre-85 laserdiscs and that 85 was the start of ANH on laserdisc.