[computerworks]

Max Mosley, Prez of FIA said this:

The HTP certifies that a vehicle conforms in every respect to the original specification of that vehicle. The vehicle might not, however, be an authentic and original vehicle. The HC, on the other hand, certifies that a vehicle is original and authentic, even if it does not conform to its original specification in every detail. Of course an original car which still conforms to its original specification could hold both an HTP and an HC. An original racing car which has been modified might hold an HC (with an endorsement), but would not be eligible for an HTP. Conversely, a car which conforms in every respect to the specification of an original vehicle can hold an HTP even if it is a recently-built copy, but can never hold the HC which is reserved for the original vehicle.

So, it does look like replicas, even scratch-built, can claim the HTP...which is cool.