OK, the mistake is the top left cornerstone...and of course, the opposite (right bottom) cornerstone is wrong too. Somewhere along the line, I messed up when I was measuring and/or sewing it on. Oh well, my MIL never even opened it up to look at it anyway. Thanks all for all the wonderful comments, at least some people appreciate the time, sewing, and thinking process it take to make one of these. Happy sewing to all..