Maus 

What do you mean that there's "far too much emphasis" placed on the two-volume nature of the book? It is a book in two volumes, which were each published separately, some years apart; you can still, today, easily find each volume separately in libraries or stores. The first paragraph clearly explains the situation of the two volumes and if you think it doesn't emphasize this enough, why don't we just straightforwardly say that it is a single book originally published in two volumes?