Rexford

Very late to this, but the correct answer seems to be that if it was done that way, then the obverse engraving would not be at the proper 180° die rotation to the reverse engraving. The way it was engraved allows for the portrait to be directly centered opposite the reverse design (which is the case for the Mature Head design, but not the Petite Head). In fact, the engraver originally started engraving off-center, and then scratched out that detail and started over. It might seem like the rotation shouldn't matter too much, but it points to the level of detail and effort put into making the model. The Engraved "Mature Head" Large Cent Design Model – Rex Rarities