When bolers get loose on the frame (like mine was) they can flex and the weak areas around the door radius crack. Also as previously mentioned it can be related to frame cracks and sagging. Cracking around the door is a common boler
The crooked door can be a sign of worn out hinge assemblies. There are rebuild kits for them. It also can be a sign that the holes where the door hinges mount have been oversized and need to be filled and redrilled (both were the case for Lita
Also the cabinet (and the closet) keep the boler
shell integrity from sagging as well and if the rivets are loose that will also let things flex. But a sagging roof can definitely be fixed with some work.
One more thing is that if the axle's torsion suspension is dead the ride will be really rough in those eggs which could result in the cracking of the frame (they were built light) and cracks in the shell. I would probably get the frame and axle
checked out first. . If it's the original axle
it will undoubtedly need replacing.
That's a lot of things I know but nothing on these old trailers is really too complex and can be dealt with if you have the time and and are a bit handy. Or if you know someone who's handy
The forum is a great source for info. Lots of kind boler folk here.