I agree with what has been said. Put the box on, put some weight on it, the bees will fill in the details.
It happens all the time. If you keep your boxes in stacks regularly, they will tend to stay better aligned in that way, but they do change shape with humidity and temperature. It is the nature of wood.
Yes, a strap would work fine. I just don't seem to have enough straps... but the big advantage of the straps is you don't have to lift the blocks off...
I whittled some thin shims and stuck them in at each corner then ran a strip of duct tape around the box. It looks pretty neat (not as in "cool"), but as in tidy. When I get a chance to change out the box at some later date, I will do that. For now, seems to be working well. I also put some blocks on top. I just felt in a crunch for time because the bottom box was a split that DID have the queen and was wall to wall brood....plus, swarms everywhere. I was just brain dead I think. I APPRECIATE all the ideas and will put them all to good use over time. :) Thanks everyone!!!