Jagsd, your blocks are amazing! I can't imagine doing these in 3" and greatly admire your perseverance. They're beautiful. My only thought on the black Batwing is that if you remove it, the one next to it with red may pop out from all the rest. But considering that there are still so many blocks to go, I'm sure the colors will balance out in the end. No worries. ;)
You may want to check Connecting Threads for solids. I believe they have some to coordinate with their Canning Day '30s line and it's hard to beat their prices - $3.96/yd. for solids I believe.