Originally Posted by SloopJonB
I would say the simplest solution would be to put them back where they were on the inside of the hull but bolt them through the hull rather than glassing them in place.
On that boat putting them on the outside would present big problems because of the heavy cap rail and rub rail.
I've seen a few boats where the external chain plates curve around the cap rail and rub rail. I don't believe this is ideal. I wonder if you couldn't just cut a slot in the cap and rub rails so the external chain plates would be flush with the hull and pass through the slot. You could leave a little extra space, a few mm, in the slot so water would run down and out of the slot, on the outside of the hull. With some SS backing plates you'd have a pretty bulletproof system you could inspect visually and service easily.