Hi Tom,
Are you member of the Airfix Forum at http://airfixcollecting.forumup.be/? Although more focussed on plastic kits, you will find Brad Hansen from California, who knows a great deal about WW1 kits and surely will help you.
We corresponded in the past as well, it was your book that made me discover the existance of Penguin kits in 1989, when I found a copy of it in a local bookstore. Am now in the last stages of a book about the Penguins. If know of any collectors that I don't know, then please pm me, would appreciate any help while the book is not ready yet .
Kind regards,
Peter van Lune
www.frogpenguin.com