1st--don't bother with the Eagnas clamps. The posts won't fit your Alpha bases.
2nd--if you look at the clamp handle (the part you squeeze to tighten it), there's a rounded part that's up against the body of the clamp. As you move the handle down, you'll see that it kind of rolls over the body to a clamp tight. I have filed the shape of that before to get a better clamping feel, so that might work. Mark is good to work with, so don't hesitate to call him.