I restored a 73 Spitfire that was given to me, and before I ever turned a wrench on it I researched the previous owner. The guy I got it from is a heavy duty mechanic and he took the car as payment for a farm job, so I knew it had a title. I sent the registered own a notarized registered letter and a bill of sale for them to sign. The letter was returned to me unopened, and then I took the letter and the vehicle info to the registration office and they gave me a title. So, four months later I could start wrenching.
I would have felt pretty crappy if I went through all that work and then some guy says hey that's my car.