canon : A word to describe something that is true to the original story; Things considered ‘canon’ are basically considered ‘true’ (in the story) [Urban Dictionary].
In 2002, James Bond Movie Posters by Tony Nourmand was published [1].
It’s hard to say if his book ever answered the title question posed above, to any extent, for the EON Productions entries. But the 200-plus pages of referenced images have proven most helpful to finding the answer here.