This page is nicely written. I answer to this:
"I've referred to the Alfonso X text as the Libro de los Juegos, but I can't track down where I found that name and other sources call it different things; anyone (Jean‐Louis?) have any pointers re this?"
Indeed, the book has several titles, it is not like a modern book with a title on the cover. Moreover it is composed of several parts, which are called "libro" (book) themselves.
"Libro de los Juegos" (Book of games) is correct however and can be used.
Among the two I vote Manticore.
This page is nicely written. I answer to this: "I've referred to the Alfonso X text as the Libro de los Juegos, but I can't track down where I found that name and other sources call it different things; anyone (Jean‐Louis?) have any pointers re this?"
Indeed, the book has several titles, it is not like a modern book with a title on the cover. Moreover it is composed of several parts, which are called "libro" (book) themselves. "Libro de los Juegos" (Book of games) is correct however and can be used.
The WP page is good (https://en.wikipedia.org/wiki/Libro_de_los_juegos) or there is also my website (http://history.chess.free.fr/acedrex.htm). An excellent page introducing to the translated text and the PhD of Sonja Musser is here: https://www.ancientgames.org/alfonso-xs-book-games-libro-de-los-juegos/