Although not exactly books per se, i have a copy of a March 1976 edition of "The Cricketer" which includes a page and 2 of edited coaching notes by S.F Barnes by L.Duckworth. I became aware of this from one of the references used in the SF Barnes chapter in "The Bowlers Art" and managed to find a copy of the edition. Its only really 2 pages long but some insightful stuff on the tactics he used. I don't know if I'm allowed to post pictures but i will if i can.
The other is separate pages of an article by The Demon Spofforth. About 8 pages and i think the article itself was in that big book by Bedlam and CB Fry. There's a few photos on his grip for the "swerver", leg-break and off-break, really great stuff overall. Again, I'd post pictures if i could.
Also! i'm hunting for a booklet on SF Barnes by Wilfred S.White, i've already missed out on an opportunity to buy a copy off Ebay
. From a small excerpt, there is a photo of his off-break grip which is so much clearer than all other photos we have seen.