I have been shooting and stitching panos quite successfully with my Rollei 6008AF/Sinar e54 and Arca Swiss ballhead (which has a pano base) . I have been shooting mostly distant subjects so far and parallex error hasn't been an issue (probably because the Rollei base is aligned with the rear of the lens so the offset error isn't that bad). However I would like to try some much closer subjects, so I need to rotate around the lens' nodal point.
Ok, so all I really need is a way to hold the camera at an offset, and that offset must be adjustable. The adjustment is very easy if it's a QR style rail which will be gripped by a clamp.
So all I really need is a RRS/Wimberley compatible rail with a captive bolt on one end which can screw into the camera base. The thread you see in the diagram is part of that movable bolt. It should have a collapsible handle on the other side, so that it fits flush under the rail.
Sounds easy. Does it exist? I searched for hours but the images on most websites were so small and blurry that I had no idea if the part was right or not.
To put it another way, what I am looking for is a basic QR plate with an extension on one side.