Issue with my egg... dome alignment off after 7 years

Hey all, had a question and was wondering if you have ever come across it.

My egg is about 7 years old and the gasket has been long gone. but now it seems like there's a bigger gap between bottom and top of dome. when I close it I can clearly see in through the slit, which is adding more oxygen and causing it harder to keep temps down and then the shut down, as it burns more charcoal.

It looks like it has an underbite, as the top has shifted back a little bit. Has this happened to anyone? Is it as simple as unscrewing and realigning everything?

I don't think I need a gasket because those seem not important... but maybe I should? 

Thanks for any help!