Looking for the original RRS BAI-AT Arca plate, which is the short one and has finger grooves. It only fits the Accuracy International AT (AIAT). Here is a representation of what I’m looking for.
Lots of pics here: https://www.ocabj.net/really-right-stuff-accuracy-international-at-chassis-plate-review/ (it’s where I got most of these pics and I hope he doesn’t mind).