Well I started figuring this out and I have to say if I did this right, Patrice your accuracy is spot on! My accuracy...not so much. If I did it right, I am going to change how I put it together because I did not have success with all the slicing and resewing. Soooooooo, I decided to make the half square triangles first then add them to the 9 patch then cut vertical and horizontal then resew into the final block. This also eliminates the hst black, which I don't like. BTW, I must really like the look of this to go through all these changes.
Thanks again, for showing your beautiful quilt.