Working on Green Bed Quilt

Here's some photos of a green quilt in progress right now. It's partially laid out on the floor of the spare bedroom and partially on the sewing table downstairs.

The floor of the bedroom is the only place I have large enough to see all the blocks laid out, so I have to carefully transport them downstairs so they can be sewn correctly. I've developed a number pinning system that seems to be working so far.

My only problem has been that even after lots of calculating, the top is turning out to be wider than the backing. I'm not sure exactly what went wrong, but this means I'm either going to have to shorten the width of the top or add some border panels to the backing. Which is the lesser of two evils? Probably narrowing the top. I think I've used up all the green backing fabric that I had and I have no idea where I got that shade of green. oh well.