And even limited restoration or parts replacement can have an altering effect on the car, which is why it's better if nothing is touched, if possible. I believe if you look closely at the suspension rod ends on 3173 you will find they are later British replacements (the replacement forgings are different from the assembly line ones). I haven't looked close enough at the car to know whether it still retains the original date coded Girling brake cylinders, but just rebuilding those can even get into revealing details. The shape of the dust boots that cover the end where the push rod comes out changed along Girling production and if aftermarket kits are used they don't have the Girling markings, etc. When it comes down to it there are thousands of subtle areas on Cobras that can reveal what was altered and it becomes very, very difficult for anyone touching the car to keep it exactly as delivered. Even Steven had limits and I know, for example, he didn't worry much about things you couldn't see, like internal engine components. Anyone really looking to bring a car back to true "day one" could have a daunting task of making sure they used the nylon tooth cam gear, Fomoco stamped bearings, and a long list of other things. It all comes down to how far becomes beyond sane.