I have both volumes, and thought that I had read it. When I looked at it, I realised that I had not - I bought another Tarot book at the same time, and had confused them in my memory. The other book was this, which I did read and which makes a lot of questionable claims:
The Le Gall book looks quite good, and I shall now read it some time. It is strongly influenced by the work of Jean-Claude Flornoy, and uses the images of his Dodal deck.