I have a 1986 bass tracker with same issue. After extensive internet research and speaking with many boat guys, I am going with a fix of the rivets with a 3m product called 5200. I have to clean the bottom first with acetone then apply the sealant to leaky rivets. After a 24 hour cure, I will scuff the hull with 150 grit sandpaper then wipe with acetone. Next step is to apply an epoxy sealant called Wetlander 3L. (Just google wetlander). Three steps of that with primer, epoxy then top coat and all problems should be solved. Whole process, including cure time should be less than a week with proper temperatures and total cost about $300.