Rob, I'm not sure I'm comfortable, but I can at least get in and drive. Have driven it some distance (Vermont Conclave and Eurofest in South Carolina were a couple trips).
The car has a center shift gearbox so there's a bit more room than with the side shift. The car came with a Moto-lita dished steering wheel; gives a bit more space for the knees. Have a factory hardtop. I think that has more headroom than the soft top, but I've never fitted a soft top to confirm.
I welded some angle iron to the front of the seat base and some flat stock to the inside of the base. Welded a piece of square stock to the bottom/back edge of the base that rests on the floor. Flattened a bit of the floor that tapers up, above the spring mount. Drilled new mounting holes. That allowed me to move the seat closer to the gearbox and further back. Also raised the pivot point for the seat back, giving more tilt. Might consider reworking the seat rails, installing longer studs so I could install tapered spacers to tilt the whole seat. But what I've done so far can be reversed by replacing the seat bottom.
I fitted a dead pedal cover over the dip switch. There was an article in one of the clubs' magazines a while back. The cover is supposed to be flipped up to get to the dip switch, but mine is flexible enough and close enough that I can just press down a bit harder on the dead pedal to press the switch.
Another thing to consider is reworking the accelerator pedal. Folks take out the short section of rod in front of the curved plate, moving it forward.