I was back to my old inset-seam-avoiding self with this one.
Print or trace the block diagram onto foundation paper, number, and cut out as in the photo.
We're going to ignore the corner squares for now.
Foundation piece the two numbered sections and trim the seam allowances to 1/4".
Out of background fabric, cut a strip 1" x 5".
Assemble the block referring to the block diagram.
Print or trace the block diagram onto the dull side of freezer paper. Because I use freezer paper for foundation piecing I just reused what I had used before.
Iron the two freezer paper sections into position on the right side of the block as below and cut out the corner squares leaving a seam allowance.
Cut four 2" squares out of main block fabric.
Lay a 2" square right side up on the table and place the block right side up on top of it as in the photo below. Make sure there is enough overlap to be able to baste the layers together. Baste through all layers leaving enough room for the seam allowance to be turned under.
Reverse applique the square.
Repeat for all for corners of the block.
Remove the freezer paper, press, and trim the block to 5" square.