Yep - that was us. If/when we do the next one, I'll cut the bottom the same - its perfect. I'd modify the back to be cut wedged from bottom to top. That being the top is about stock and the bottom taken in the 1-3/4" ea side to match the bottom. This would give a perfect fit with the side panels. That being said, the seat is really comfortable and its not an issue with two big guys. Leg room is a bigger issue and Cooter has that solved with the stretch body. Dad is already thinking about one of these seats or similar in his '30 Model A Tudor which is next on the build list.
I will say I'm a huge fan of how we made the bottom swing up to allow access to the battery, tool box, fuse panel, and small storage area. Makes the car that much more usable with some room in the bed area for a day bag and chairs.