I'm going to get all rocket science-y on yo ass now...
I don't know what Nutomic had in mind for the theoretical use of the rocket, but judging by the shape, it looks kind of like a cruise missile. In which case you need wings, not those little fins.
Here is a tomahawk for instance. If he was going for a nuclear missile though, then the huge model valve have is more accurate,
as this image illustrates. The other obvious option is the traditional shape used by solid fuel rockets and amateur rockets. I'm sure you know what I mean. Loooooong cylinder for the body with 4 fins on the very bottom.
With that said, I suggest an adapted nuclear missile design. Elongate the nose cone or even make it into long point, and add 2 sets of 4 fins. One set at the very bottom and one a little beyond half-way to 2/3 up. Also, fins should be what I can only describe as truncated triangles...
basically this.