LOVE those old tins!
I met the guy that restored this Cadillac tin skiff - pictures attached. I tell you, if I used my tins on trailers, instead of 24/7 moorings, I would have bought it. It was beautiful! He replaced that motor and bought a Nissan e-start 25hp controls motor off me, as he wanted the reliability of a newer motor, but lamented the old style OB motor look.
On my suggestion, he found an old Evinrude "Lark" parts motor as shown. I told him he could cut a plywood template,cut-out to affix to the existing top of the Nissan pan, then cut off the top of the Lark pan and fasten that old pan to the top of the plywood. Then he would be able to remove the Lark cover. It worked! Yeah, there was that funky transition between the newer lower unit and the old style cowling, but one would really have to know old OB motors to figure that out. Believe me, it looked far better than it sounds, haha!