here is one that is on my design wall. Same idea. Note that on the blocks that are not grey, I added a small grey border before the shadow. I arranged them in rows, measured the widest one and then added background strips to make it that size. There is a close up of a block also to show the shadow better. Hope this helps!
quilt top
[ATTACH=CONFIG]162339[/ATTACH]
close up of block
[ATTACH=CONFIG]162340[/ATTACH]