So...this morning I took it apart. Separated all the blocks and discovered they were all slightly different sizes and shapes. Uh - was I drunk or just tired when I sewed them together? Most likely, just in a hurry. Not a good idea.
I trimmed all the blocks to the same size (5") and tried another arrangement, without sewing them together.
Better, but not much. The blocks were too big arranged this way. They needed more space around them but I had no more of them and wasn't about to make additional ones. Other fish to fry!!
Then - what if I put space between the small units and played with a sort-of alternate grid? Here is what is on my wall now. I still needs more negative space around it, but I think I'll stick a fork in it. What do you think?
Of course, once I sew the pieces together the whole thing will get smaller and may change a bit - but that's okay. It can't be worse than the first version!