The diamond blocks could be two blocks. Make them with hte TRI-Recs rulers. My class is just finishing a quilt called ring of stars from McCall's Quilting thee best of American Quilting Jan/Feb 2011. We found that making the side pieces 1/2" longer than triangle piece helped the block go together easier. the side pieces would be the red in your pic.
Great job doing all the picture work. I'm still trying to figure how to do this-add a pic. Pegeth