I like your block. I turned out nice.
http://www.caroldoak.com/pdfs/LacedStarVariation.pdf
This looks similar and finishes at 12".
http://www.caroldoak.com/pdfs/IntrotoPaperPiece2.pdf
If you enlarged this when copying it you could get it to be a 12" finished block. I am thinking enlarge at 150%.
I hope this helps.
DeeDee