Its a difficult one to be honest, there is so many different rules and regulations about what is classed as a VHI, my escort has a 1600 xflow instead of its original 1300 crossflow, still an original engine though, brakes are m16 calipers, although new remanufactured parts, still ford fitments, my suspension ok is GAZ gha so thats not original, wheels are rs 4 spokes, not original to the car but original ford wheels.
Im a mechanic by trade and to me my car is still an original mk1 escort, but to others its not.
As for original body shells and all that crap, with the exception to some, how many people out there have got an unwelded original car with period panels, to me the panels being produced now are the same if somewhat better than ford produced back in the 70s.
So many ins and outs of this.
Ill be interested to see what other people say.