BobStrawn
>The open side works better for a narrow blade than for a wider one in my own experience. I regularly make one shot planes just to try an idea out,so I have had ample opportunity to learn from my mistakes. The problem that I have experienced with the side cut, is having the blade skew and then cut a gouge. If you drive the wedge further, you risk cracking the opening or deforming the original shape. In any case where the wedge is forced from above, as the blade digs in the wedge loosens. With a side cut plane, the open edge is more prone to loosening than the inside edge. This is less of a problem with a narrow blade, especially when the edges are rounded.
Woodsmith has a plane kit using a Hock blade, that I have found very useful in rigging planes. Http://www.woodsmithstore.com/handplanekit.html The blade is clamped by the chipbreaker. The chipbreaker is held by a screw from below. This method causes the least distortion, or the most consistent distortion, that I have experienced, and makes the side cut work fairly well. Here is an image of a plane (not a side opening) using this method. In this case this wedge type allowed a low angle woodie to be stable.

Bob