Glory Boxes

I am working on a second sweatshirt for myself.  The Scroll Sweatshirt was a stretch for me, since I gravitate towards orderly or geometric patterns.  I wanted to be back in my comfort zone with this sweatshirt - a quilt block or three, as I've done in the past.  I stumbled across a pattern called Glory Boxes years ago but have never had an opportunity to use it.  I thought a Glory Boxes block in light colors would look great on the dark green shirt, especially if I cut away the background to let the sweatshirt show through.

At first, I thought I could just sew the pieces together with the blank spots in it, but soon discovered that keeping it square and dealing with extra seam allowances was nearly impossible.  I decided to sew it as a full block, then rip out the seams and cut away what I didn't want (the white pieces).  That has been working well so far.

I am still debating how to attach it to the sweatshirt.  I planned to hand stitch it to the sweatshirt, but I've been having trouble turning under the outside 1/4 inch.  Seams get bulky when dealing with a small block.  So I may cut away the extra seam allowance and zig-zag stitch it to the shirt, like how I sewed the nine-patch blocks above.