Closing the Gap

I had this problem once, although with vacu polystyrene cobblestone. I went to cut out all the "stones" cut in half by the edge. When you then put the two pieces together try to get "stone-sized" gaps". Then I made several "stones" out of sheet styrene and set them down using some putty. If you avoid straight line joint, the human eye has more problems to recognize it, and that's what we want. Hope it helps, have a nice day