Thanks guys! It was a blessing to be able to sew today. I did get so much done.
I finished the 16 inner unit blocks. I didn't like the appearance of the back as I did all that bobbin work & the tails of the Razzle Dazzle show. So I cut out more 7 1/2" black squares and added that to the back as I sewed the blocks together.
What you do is cut a 1 3/4" x 7 1/2" strip of fabric & a 1 1/8" x 7 1/8" strip (I chose to use more black.) Fold the 1 3/4" strip in half & press. You pin the folded strip to the front of the block on the side you are going to sew to the next block - like right side of #8 & the 1 1/8" strip on the back of the same side lining up the raw edges. Sew a 1/4" seam. Press the back piece out away from the block. Now you pin block #9's left side to that back strip & sew it. Press it all nice & flat. The batting/block of each block will meet in the middle. Then you press the folded strip on the front over to cover the join. I am sewing it down with a decorative stitch in black thread. I am sewing both sides of each sashing.
Yes, this creates a small (1/2" wide) sashing between the blocks, so they are really 7 1/2" instead of 7". I have the 4 rows sewn together. Now I need to cut 3 - 1 3/4" x WOF & 3 - 1 1/8" x WOF strips so I can sew these 4 rows together.
Then the center unit will be finished. The only thing you can see on the back is the decorative stitching I used to sew down the sashings.
There is a tute here that sort of shows it, but her picture of the joined blocks isn't very clear. I should have taken pictures as I went along. I'll try to remember to do that while I join the rows. Technique is the same, just longer seams.