Love the pinwheels and layout. Have you considered adding some embellishments to the SBS? I'm thinking a band across the hats or embroidered details. I'm kind of spoiled with SBS because I inherited 13 vintage ones. Here' what mine look like.......
http://www.flickr.com/photos/5800297...7626558912825/ I just inherited the blocks, half of them unfinshed and that's what I'm doing with them. Just some ideas since they are approximately from the era you are designing with.