Michael Coate has written articles about the theatrical releases (specifically what theaters and runs) of the films, some of the articles have pictures:
http://www.in70mm.com/news/2003/star_wars/index.htm
Another article from the site with pic:
http://www.in70mm.com/newsletter/2000/62/dolby/index.htm
http://www.fromscripttodvd.com/star_wars_a_day_long_remembered.htm
http://cinematreasures.org/news/16528_0_1_0_C/
These two links are other places which could lead to people who might have photographs/info of the movie, or other information helpful to SaveStarWars.com
The 70mm collector film cels from the 90s, are those of useful reference?
http://astrogalaxy.blogspot.com/2008/05/star-wars-film-cels-posters-and-cards.html