I looked at the pictures in the link you have, and I can see why a beginner would have problems understanding the dimensions. The pictures show the FINISHED block without the 1/4" seam allowance around but repeatedly say that it's a 12 1/2" block, which is the UNFINISHED dimension. I think you're on the right track now though, with 1/4" seam allowance being used to join the blocks.

Thanks, I think I'm on the right track now. Not perfect but close to it. :thumbup: