The weathered look of the shiplap boards are beautiful.  The only small change would be that the design repeat would not have the one small square with the nail design on it on that line.  Once out on the accent wall, it kind of takes away from the shiplap board look and the continuity and wallpaper instead of real shiplap gets noticed a little more.  Once I have my wall hangings and pictures back on the wall there may be a different opinion.