Lyman Platt Books
Stuart,
I found some Platt books at: www.familyhistoryland.com/books.htm . I don't know if they still have them. If you can't find them, I could copy some sections out of my book (if you read Spanish) and mail them to you. My copy of the book is stamped on the back "Hispanic American Genealogical Association, PO Box 2650, Salt Lake City, UT 84110-2650", but I couldn't find that Association listed in the yellow pages.