I am always amazed at what blocking can accomplish. If you have a spot--spare bed, empty floor area--and can lay out the top (even if you fold over the outside parts and pin or tape them down-you really just want to stabilize the area that you want to block) then spray with plain old water and let it dry. I have shrunk (and stretched) blocks this way as well as squaring up very wonky panels. If it doesn't work, nothing lost.