Thanks.
Yes both ends of the top bar are tapped 6-32, same pattern for consistent setup. The front side (with the notch) is intended to accommodate different sized/shaped stops. I just made 2 for now of different depths. For example if I have a thin part, then the appropriate parallel will also be high. So the stop must have a shorter overhang without conflicting with the parallel. The other end of the top bar has the end plate bolted on. I tried to get the center of the clamp foot aligned close to the jaw corner as possible so tightening minimizes any coupling moment. Endless fun for a couple bucks of materials LOL.