Vintagedr,
Dave Friedman was the official photographer for Shelby American. He is the author or co-author of at least 6 Shelby related books.
There is a rather expensive out of print book by Peter Brock, Dave Friedman and George Stauffer called "Daytona Cobra Coupes". The book came in 2 varieties, a normal one and a limited edition with a serial number plaque and signed by dozens of Shelby employees, drivers, etc. I think the normal edition of the book usually sells for over $1000 when one comes on the used market. I think the limited edition usually goes for at least twice as much. But if you are really serious about knowing the story, that is a book you should read.
Luckily for you, another book that was out of print for a very long time has come back into print. It is called "The Cobra-Ferrari Wars" by Mike Shoen. Since it is back in print, you can get yourself a brand new copy for $100 direct from the author:
THE COBRA-FERRARI WARS - AWARD-WINNING CLASSIC DIRECT FROM AUTHOR
If you find yourself looking for books that are not so specific to Daytona Coupes, there are some general Cobra books written by authors that hang out on this site. One of them is Trevor Legate. He seems really cool. Wallace Wyss has apparently returned somewhat recently, his new username is something like "historybuff".
Ken