Its kind of like researching your family history. No one is going to be able to give you all that information. You have to ask the person who you got it from about who he got it from. and so on and so on. However, you can get your car's birth certificate (in a manner of speaking) from Marti Auto Works For $45 you can get the deluxe report which includes all the build infomration on the car including, when it was ordered, when it was sold and what dealership sold it (but now who bought it). If your car was built in Detriot, you can get a copy of the original window sticker.
I would check w/ the State of Michigan. Mustang Monthly had all the state's title info in the Dec. '05 issue. Try looking at Michigan's web site www.michigan.gov/sos . Kansas had a form to fill out & request copies of past titles. It was a measly $15 per title search. I did this for both my '65 & '66 Mustang. Only found 1 P.O. ( before guy I bought from ) for '66 & amazingly EVERY single owner ( I think I'm #7 ) back to original owner for my '65 fastback. This is cuz the car was always titled in Kansas. I even found the guy's name in the local phone book & called him. He was a college student in '65 so is about 60 now -- we chatted for quite a while. I even visited him about a month later at his business. He was quite surprised the car was still around -- much less in the same town in which it was sold new in. Anyways, check w/ the state of Michigan, but then you will only learn about title info for Michigan -- so who knows how long back the car was registered in Michigan. This is one avenue.