Actually there a a new company that has started to publish a series of new books on Japanese leather carving with inspiration from American Leather carving primarily from the Sheridan influence. These books are pretty thorough and though in the native language they have probably 3 times the amount of pictures explaining the process then another book that I have seen.
The publisher is a Japanese company called Studio Tac. How do I know, well, I happen to own about 12 books from this publisher that i have collected over the past two years. There is probably another 12 that I am missing or have no desire to purchase due to the subject.
To help you do some research, here are a few spots where you can look at the books or start your collection.
* www.goodsjapan.com
* eBay seller: CharmingBabe ~ She is selling the Chinese translated version of these books.
* Craft Japan
* Seiwa Company
There is one more company, but I cannot remember it right now. Old age.
Good luck! Sam