Originally Posted by Jingleberry
Possibly if you can clamp it down while sandwiching it you can gently tug it into being straight and try getting the top and those edges to be straight and put in tons of safety pins and when quilting only take out a few pins at a time and hold taunt with hands as you quilt it. Do the above on each side. I almost only do FMQ and think it hides alot of flaws after the quilt is washed and dried. Kind of hard to put into words. It is beautiful and I'm sure you will be able to get it to turn out and it won't be noticeable when it's finished.
Jingleberry, thanks for this. Sounds good! I don't have a table big enough for for clamping but I have a wooden floor to tape stuff to!
I'm planning to MQ large meanders across the center and I've done that on my practice sandwiches without even taking pins out, just flowing around.