"The Rex is a Swedish brand made in the town Smedjebacken, also called Norden and ( what I think ) is also a copy of the Evinrude Rowboat Motor from early 1912.
I have one in my collection. Unfortunately, they messed with the lower unit and tank. The picture (in the ad) shows a rudder, probably an option like the Evinrude had as well. Mine has the original aluminum muffler including the embossed name REX."