I'm at the cabin and my micrometer is back at home base. If JVZ is logged in, he will have the answer. My impression, however, is that the diffierence, if any, is unnoticeable.
Edit: I just found a spare set of black carbon fiber grips in my range bag. The difference between them and the VZ grips is that the CFs are flat across the width while the VZs are beveled. The width at the center, however, appears to be essentially the same. Again, however, I do not have a micrometer with me at the present time.