The studio may have felt the original pressbook was insufficient to properly promote the film, and found it necessary to update it.

The b/w example has the phrase at bottom about it being an advanced manual based on the early triumphs of the film. Assuming that phrase is not on the color one, I'd suspect the b/w version to have been released later, and contain ads and ideas proven to work best for previous showings. I would expect much of the contents do be different in each of them.

check with bruce-aka-movieposter,if he's still here AT ALL. if not,PM me.

LET'S GET PORKEYED!!! I HAZ CHOCOLATE TOO!!

Thanks for the love, SWIMBO, even if it is second-hand! 

I have had a (very) short conversation with Bruce about this and other pressbooks I have.  Bad timing... I guess he had some auctions ending or something.  Bottom line, he was either whelmed or underwhelmed ~ sure seemed like the latter.. even though most had not appeared in his historical database EVER. Same with Heritage ~ who basically told me to find some braided hemp and void myself in a vertical vector. (It seems they forgot to mention on their website that there is a $5K threshold (by their estimate) for their innards to be tickled and NO, they do not actually provide those evaluations they tout on their webpages.)

Had better luck with Bonhams Auctions.  Met with them in person today and they expressed sincere interest and excitement in this material and we are talking about inclusion in their next feature movie memorabilia auction.  But then, they took the time to actually LOOK at what I have.... 

Of course, like ebay & everyone else in the biz, they will take their healthy cut off the top.  If your friends are sincerely interested in this type of material, they are certainly welcome to contact me.  I will be happy to provide photos if requested.