Def no argument here with how George does it ! The problem is , what kind of access do you have to all those areas once the deck is dropped on ?
As to your original question , if I recall correctly , the spacing of the original factory deck/screw locations is about every 18 inches or so on the St T. Yours is probably similar. It rarely works out in real life though when you go to put the rub rail on with it's pre-drilled 6 inch centres and you have to make slight alterations on the 'big day' when you least want to.
Don't forget though , this is your chance to use a good sealer on the hull / deck joint while you're at it and as always , I don't recommend 5200 unless you never intend for anyone to ever go through what your doing now again.
Just because something's old doesn't mean you throw it away !