I've had the seats pulled out and apart a couple of times.
I didn't take any pictures to reference.
The lumbar is a single unit where a cable pulls down and expands the lower back support. The lumbar support is a wire truss. The support is mounted by means of wires right and left. The support wires are pretty stout.
Mine feels pretty good left to right for a manual lumbar.
While I had my seat apart, I reinforced the bolsters with duct tape to firm them up, almost to much. I tightened up the back support wires a little too. You have to partially disassemble the lower cushion to even start on the seat back.
I can hear your thoughts, removal and teardown on the seat is like a 3-4 on a 5 scale process.