Ray,
I have a really good book called "the Ultimate Koi" by a guy called Nick Fletcher it has two chapters called "The history of Koi" and "Koi then and Now" - may pay you to borrow this from a library to see if it is of any use.
I'm sure you are past this in terms of knowledge but you never know.
Also,
Here in the UK a guy called Peter Waddington has done two books called KoiKichi and Koi2Kichi. They might be of use or you could try contacting him directly to see if he can help.
He has a website
http://www.koikichi.com/index2.html sure you will be able to find a contact us section here.
Notice you live in San Antonio, Texas - i will be there myself in October for the World Skeet Championships. Plan on Checking out the Alamo. Anything else that is a must not miss thing to do while in San Antonio. I will have about 3 spare days while not competeing.
Hope i have been a help.
Regards,
Greg.