Actually the Doughdish is the only exact replica of the original HMCo. Boats. The Cape cod shipbuilding version has a slight curve to the transome to make it easier to remove from the mold - as well as being quite a bit lighter. Only the Doughdish is accepted for racing by the H12 1/2 association.
As has been discussed - Cape Cod Shipbuilding owns the rights to the WOOD builds of these boats. For more info click the Registry link above and see the documents section.