It would seem that your friend has honed in solely on the size number on top of the handle being raised in bas relief in making that assessment. However, if you take a look at similar griddles (called bacon fryers) in the Martin section of the RB, you'll see that the underside of the handle is completely different, that the shape of the depression on the handle top differs, and that KS&R didn't use bottom gating. The handle design on yours is common to several unidentifiable mid-19th century pieces.