A couple of comments in response to questions about the relationship between Spencer Brown’s Laws of Form and the broader scope of Peirce’s Logical Graphs.
George Spencer Brown mentions Charles S. Peirce and also Christine Ladd-Franklin in the chapter notes, appendices, and references of his Laws of Form. Just scanning very quickly, I find references on pages 90, 111, and 136 in my copy.
Almost in spite of its extremely elegant style, Laws of Form did succeed in reviving a visual way of looking at logic that Peirce had pioneered but that few other logicians took up with any success in the intervening years. It drew out and clarified a number of insights into the mathematical forms and methods of logic that Peirce had the depth of vision to peer into but did not always have the opportunity to develop as far as possible.