interesting. i hope that someone has either already read or will now read this book and get back to you.
there is a lot of literature on anarchists and schools, including a school called stelton, one in spain called the modern school (francisco ferrer was martyred for his work there), and so on. the info you get from researching these wouldn't be a direct review of gatto, obviously, but it might give you the info you're looking for anyway.