Sounds like you're getting lots of direction. I did a '77 27' Catalina in 1999/2000, bolts chainplates, port gaskets (general UV damage). In addition to the tech advice, bedding compound is muy importante'. Ask around about bedding compounds and their correct applicaions, cleaning off the old compound is key, solvent will go a long way in attaining clean surefaces.
When bedding the bolts/chainplates you're better off to let the compounds set and dry completely then tighten all bolts. If you tighten before it sets and dries the compound is squeezed out and water leaks in.