Welcome TRE J!

Mine is an 84 as well, and it does seem like the cabin roof sags toward the middle. *Mine is as solid as, well, uh, it is solid, it just doesn't shed water very well.

There are a couple of drain holes under the hatch slide that can get clogged, check them to see is they are open, otherwise, don't keep anything you want to keep dry under the hatch area in the cabin. ;D