I just checked this out for the first time. It's such a neat pattern and you've done a great job piecing. My thought might be to straight stitch on your borders a 1/4" from each stitch line (sort of like trapunto) and maybe echo around the centre of the block maybe three times. I went to Paducah National Quilt Museum in March and it seems like all the new hot ideas is to stitch with metallic thread. I'm very interested to see what the "winning" suggestion is going to be.
LinC