It's tuff when all four sides are different. I had that happen to me. Only there was a much greater difference so I had to give it back to the owner. She took tucks in the inner boarder and gave it back to me. I was not aware of it being the same quilt until I had it on the LAM and saw the tucks. I'm talking 1" tucks and several of them. I quilted it anyhow to the best of my ability. I was not pleased, but it was what she wanted. I was told many years ago that
"you can't make a silk purse out of a sow's ear"
Good luck, I hope it works for you.