Normally, unmarked CHF have a thin outline where the TM was excised. One wonders if there was some kind of slug with the TM on it that was applied to the pattern, perhaps replacing the Favorite Piqua TM, and/or a blank one for unmarked ware. Since CHF acquired FPW patterns ca. 1934, their hollowware production would be from that point to some later time that's not quite certain. 1940s, maybe?