RZ67 back is arched

So, I have one 220 back that I shot only one roll with because it ended up having a light leak. Wanting to shoot more with it, I wanted to see if I can temporary fix the leak and found that the shell part that goes over the insert has some play in it. I've swapped the insert with another shell and there is no play. Any thoughts on if there is a fix or just deal with swapping and/or buy a new one.