Have you searched this site and links ?
http://www.vintage-mustang.com/

I have a book I bought many years ago.  Name  The Mustang Recognition Guide.
The author was Donald Farr I believe.
This book listed a lot of the standard and optional equipment for the 65-73
Mustangs.
If it is still in print, you should be able to get it from a Mustang supply
house like California Mustang.

Erich

Most mustang parts vendors have available a small 2 page paper  book(
printed by Osborn Reproductions) that list all the factory and dealer
options for each year. I think they run about 5.95 retail. Also you need to
know that ford options came 2 ways. RPO or regular productions options, were
factory installed options. DIO or dealer installed options were installed or
availalbe at dealers. Some of the options could be had either way. Ford also
had a factory muscle parts program availalbe in the mid sixties. Many
options not listed for the mustang were installed by dealers prior to first
sale and the arguments at national shows have raged for years, about what is
"original" equipment.