Ed, my seat is indeed bolted to the floor. The car fits me and my head is BELOW the windscreen. I have fabricated pedal extensions so that my 5'3" lady can also drive it. Her arms are almost as long as mine so the seating position/hand placement still works. It's just the short legs we have to deal with, specifically the clutch travel. The clutch needs to go almost all the way to the floor.
Years ago my friend Walter drove my car and I followed him in his 911. It struck me how you couldn't even see his head in front of the headrest. He was 5'9", same as me. It's the proportions though, he had at least a 34" leg with a short torso. I'm thinking Stan has the opposite problem, short legs and LONG torso. He'd be good if we could re-make him with a shorter neck........
None of this would be so if I had a plexi screen. Then pretty much anybody would be above the screen.