[size=12]It's Griswold, yes. It's a round handle griddle, though, not a skillet. It looks to me like you have a pretty early style handle on this, but there are some out there that look this way. The larger teardrop-shaped hole in the handle is more common.
I'm guessing it probably dates to something like 1912-1918 or so, but I'm making that guess without running up for the guidebook, so I could be wrong on that.[/size]