More than likely 5652. The one in my shop. White with currently orange interior. The one at Indy was white. There was one other white prototype. The build sheet shows red interior, but I haven't tore into it to see if that is how it actually was built. Things might have changed when it was updated and sold by the factory in engineering. When restored, it will be as it was when first built including lacquer paint which I already have acquired.