Depends on how bad the rust was, and why it rusted to begin with, and what does treated mean.
Not trying to be mean, but if it rusted because they are regularly sprayed with salt water
due to the air ingress into the hull
and that has not been fixed, it will reoccur. And if threaded means sprayed with rustoleum, it will reoccur.
cracking can be common and not indicative of much, or it can be cracked cause there is a problem with the underlining glass, you need a good surveyor
, they should be able to tell you to walk or not.
Don't be upset if the surveyor
tells you to walk, if so likely you have found a good one, and they may have saved you a lot of grief and money