Iwantone,
I wouldn't consider a doner cobra a mustang. I have a friend that just finished building a factory five. He used mostly new parts on his car. It turend out to be a beautiful car and it is an excellent example of a Cobra Replica.
I too spent lots of time doing research. I have a pile of research documents that you can have. If you would like to meet some time I can hand over my 7 - 10 years of research.
Don't forget to go to
www.cobracounty.com and buy the latest book by Curt Scott on the golden rules of puchasing a cobra. This will provide you more information than you can imagine. It will teach you the real questions you need to be asking.
Make sure if somebody give you one that you get the most recent updated to the book. If you have a chance to talk to the author take it.
good luck and have fun