This Jeep did not come with a driver's seat at all. My father built one using an old school chair and 2x4 but that fell apart from exposure.
I found a small folding jump seat somewhere that I thought could be used. But there was no frame or way to attach it to the tub. I took the school chair off and bolted the jump seat to the wood frame. But that was still sketchy over the gas tank and it still had no seat padding.
A friend came through with some leftover CJ2A parts including two seat frames: a complete one and a cut-down frame. I assumed this would solve the seating issue once and for all.
The new frame appears to be a CJ3A frame, judging by the shape of the frame tubing and other photos online. It bolts right up to the floor in front of the tank but will not reach the bracket on the rear wheel well. It rests on the gas tank before sitting correctly on the bracket. I don't know about the gas tank - if it's original or an aftermarket that might be taller. The rear post also does not reach the floor. I'm not sure what's going on here.
I can shim the rear post and the frame to the wheel well with wood and everything lines up nicely. It's not a permanent solution but will be OK for basic driving in my driveway.