Fighting leaks seems to be a common struggle, and an ongoing battle. At least for me. Keeping “on top of it” is important not only because of the damage caused by penetrating water, but also because if you have multiple entries it is really difficult to find and correct the faults.
One source of entry I discovered in recent years was due to failing sealant at the shroud deck plates (on our Classic 35). The water then runs down the internal bars connecting the shrouds to the hull.
It turns out these are quite simple to cure: remove the shroud, unscrew the bolts holding the plate to the deck (no need to remove them completely, just a cm will do). Lift the plates from the deck, clean off the old sealant and replace with butyl tape.
This seems to do the job.
The problems caused by leaking toerail fixings is a much bigger headache. I had to get them removed, and rebedded TWICE (27 years)… expensive and very tiresome. Does anyone else have this problem?