I just measured for these stacked curved stairways. My camera doesnt do the size or depth of the “hole” justice as it is 22 feet down to the basement floor.
I have some serpentine railing to connect to the two arched balcony sections. It will be a fun project.
I built a stairway for this guys brother about 10 years ago. Word of mouth advertising can be the best or the worst advertising to anyone self employed!