A few years back I bought a 1937 Chevy,2 dr sedan that had late model running gear in it,350,350.I could not find the VIN anywhere on the car.I knew the guy I bought it from was honest and he had owned it for about 20 years.I stamped the VIN no.from the title on the frame.Never had a problem with it.I sold the car to a dealer,and told him where the no.was.He said this was an OK solution.You might want to check that out.