Model 500 cover not going on straight.

[HarrySmith]

I would agree that the dial is the cause of your problem. In your second picture it is it looks like the dial is not straight in the case. Try Larry's idea, remove the dial completely and see how it fits without it.

[newskeeto]

Well, I tried it without the dial and it was still uneven.  I then put a shell from another phone on it, and it was nice and straight (hopefully this is not just because the shell from the other phone is hard plastic).  It is almost definitely the shell.