Your first idea is the best one, but may be more work
than it's worth. If the centerboard
is from 1982 and only has surface rust, you may get by with simply sanding
that off and going with Rustoleum. Try it for a season and see what happens. If the rust gets a lot worse you can give it the heavy-duty treatment. If not, you'll have more time for sailing.
You do not want to leave a boat with the centerboard
down on a mooring
. It prevents the boat from swinging into the wind
, and can lead to its capsizing. I have seen this happen with Lightnings, which are bigger and heavier than your Javelin. (In Larchmont, btw, just across the water
from you.) If the centerboard is left up when the boat is moored, it won't be sitting in the water
all the time, so may rust less.