I like the tiles a lot, they bring it together. As far as together I believe if it was truly 1/8" out, your corners would have had pretty major issues lining up as tight as they are. My first though looking at it was an optical illusion brought on by that grain pattern. Anything with such prevalent grain as that, is sure to draw attention to itself, and that, this is longer, is kinda a thing you get with it often. Measure each side very carefully, and I doubt you will find that 1/8".

Cool box!!!