With regard to hooks rotting out - I landed a bass at Hurst last autumn, it was very long but extremely thin and emaciated. It weighed in at 3lb when normally it would have been at least double that. On examining it more closely it had an old looking bronze hook inside and across its gullet, with line attached. Even though it had taken my tiny bait on a size 4, hooked in the mouth, I believe that the other hook may well have been the cause of the fish being so emaciated, possibly preventing the fish from swallowing a substantial meal. I'm sure other anglers have also landed fish with old hooks still in them.