Would mr x be happy if he paid top money for a mint genuine original car to then find out it's actually a base model shell that's had its I.d swapped with a much more desirable I.d?.
I wouldn't and if the seller declared it before purchase I wouldn't bother going to see it..
Pretty sure if it was a new shell that is unstamped it could retain the donor cars I.d but anything else is ringing.
Plenty mk1/2 escorts out there not wearing their original I.d though and you would never know.