This book should have been a masterpiece, and I'm a little frustrated that it wasn't.
The format is the problem. Zeman speaks in generalities, occasionally illustrated by a cartoon (which he refers to by page number so you can go look at it, at least). The art is in no way centered, and I mean that quite literally. Over near the margins are small cartoons, usually with grudging brief explicatory captions. Not everything is translated.
Rewrite this whole book. One or two cartoons, huge, on a page, and then talk about each one. Too much of Zeman's text covers what you can find in any history book; I'm here to see caricatures!