Number 2, the United States ten-cent 1847 postage stamp and Number 4, the 1875 ten-cent reproduction of the 1847 postage stamp are much easier to tell apart than the five-cent stamps. On the reproduction the eyes have a droopy, sleepy look that is clearly not present on the original. This is the way most experienced collectors differentiate these stamps.
Further, the reproductions are shorter than the originals. On the reproductions the shirt collar is not nearly as discernible as on the original. On the reproduction, the outline of the coat points to the "X", while on the original it points to the "T" in "TEN", and as with the five-cent stamp, the engravers initials "RWHE" are much clearer on the original than on the reproduction. The reproduction was never valid for postage and while it is truly not a postage stamp, it is included here since it has been given a prominent position in U.S. philately by the Scott numbering system