I had a similar thing happen. I was embroidering blocks for a baby quilt with a circus theme. I got ready to assemble the squares and realized I was one block short including my signature block in the corner. I had done one design of each and didn't want to duplicate. Finally found a similar design in another collection of the right proportions and added that. In the end you couldn't tell which design was the odd one, even me. So just add one in a corner with your signature or some cute phrase that would fit the person you're gifting. No one will be the wiser.