I hate to correct myself unless I think I'm mistaken, and in this case, I may be.
Initially, I came up with fourteen sections per shoulder. This was by counting the sections although some of them are obstructed by the shoulder bells. If there are fourteen sections, then they would be 5/8" apart from each other with the two triangular ends being just a bit bigger.
Using this pic, you can easily count ten sections which stop right around the center of the shoulder bell. I duplicated this with a paper model coming up with a space between the stitching of 7/16". If this is correct, then there would be
twenty sections per shoulder, not fourteen.
I thought that sounded like too many, so I checked a few more pics trying to make scale references. The result, using the pic below, is also 7/16" sections.
So which is right: 14 @ 5/8", 20 @ 7/16", or possibly somewhere in between? I'd like to get a few more opinions on this.