Didn’t read all the threads, but second the suggestion that you measure the middle and both sides. I would also check to see if anything is going on with the pieced boarder. On my avatar I had to adjust the pieced section of boarder to get the size right. Lost a few points, but gained a straight boarder. It is obvious that you have many hours in your quilt. Take the extra time to get the boarders so you like them. It looks like you have more fabric than will quilt out easily. Just don't give up on quilting.