That's not a bad reference, but I much prefer Michael Naglav's book Hofner Guitars Made In Germany. The text is in German, but much of it carries an English translation on the same page.
There's a matching volume that has a wider field, Schnepel & Lemme's Elektro-Gitarren Made In Germany. Again, the text is in German, but the book comes with an accompanying booklet with the complete English translation.
In each case, what makes these books so useful is the [cliche alert] German thoroughness with which they have been researched [/cliche alert] and the very detailed photographs.