Thanks for that information. I haven't begun my restoration of the Cougar and so haven't dismantled and cleaned any chassis parts to see if any of the markings are still visible. But I know there are no build sheets. The other part that would have distinctive markings would be the drive shaft. Do your build sheets also indicate what those colours would be? My rear leaf springs appear to be original but I can't find any numbers stamped in them similar to my Mustang.