I just bought a 2018 JL Rubicon and the previous owner (or someone) took the roof rack off. Luckily, the mounts are still connected. I'd like to get the same rack so I can just redrill the holes and run/seal the bolts.
Looks like you already identified it. You are missing 4 interior brackets and the 4 exterior brackets that bolt to the rhino rack pioneer platform. Also the 2 brackets on the hardtop glass hinges are from a different unknown product.
I just got this a couple of days ago and have not had a chance to install it yet.
My rear brackets look a bit different but I have a 2 door.