tenders
Innocent Bystander
Using somebody else's handrails would not necessarily guarantee that the mounting holes are in the right place (if you were thinking about through-bolting them to the external handrails). They will also probably look bad.
These are not too expensive to buy pre-made from West Marine, or you could make them yourself. You make them in pairs from a single piece of wood, or StarBoard, using a hole saw to make either side of each loop and a table saw or handheld jigsaw to cut out the intervening material and to cut the piece down the middle into a matched set of two. Don Casey shows how in This Old Boat.
These are not too expensive to buy pre-made from West Marine, or you could make them yourself. You make them in pairs from a single piece of wood, or StarBoard, using a hole saw to make either side of each loop and a table saw or handheld jigsaw to cut out the intervening material and to cut the piece down the middle into a matched set of two. Don Casey shows how in This Old Boat.