Rob Fitts has just published an eBook called "An Illustrated Introduction To Japanese Baseball Cards". It's a 82 page pdf that covers the history of Japanese baseball cards from the 19th Century to the present. As the title suggests, it's lavishly illustrated with examples of cards throughout the years. If you follow the above link you can see some sample pages and download the book - it costs $4.99.
The background of the cover photo is a 1977 Yamakatsu card of Tsutomu Wakamatsu. It's from the JY3 set, one of the oversized sets Yamakatsu did in 1976-77 - it measures roughly 6 3/4 inches by 9 3/4 inches. I thought I'd share the what the original card looked like:
