Remember I said there are interesting looking seams on these blocks? (kinda dodgy looking aren't they) Well the blocks now need to be trimmed. Select the smallest looking block; place your 15 1/2 " square ruler over the block, mark off the centre block of the star with tape. This will then be placed on the same section of each block. Now, trim off the edges to make your square.
I am going to use the flag fabric around the border. Will probably bind it in either red or navy.