When my N37 was being built I visited the Siltala yard. They had changed from toe rails to a metal angle bracket along the side of the deck, similar to that seen on Hallsberg Rasseys. My 33, which Dave Babsky now owns, had a solid but jointed teak toe rail and a solid toe cap. By 2000 Siltala had gone to laminating their teak especially at bends and I saw in the factory several jigs made of plywood with dowel pegs for producing the hand rails. I think obtaining a solid piece of teak from a tree with the right shape is going to be difficult. Kai Gustafferson once told me that Siltala had made a very big investment in teak prior to the international restrictions on exports from Burma. They had stored it deep in the forest near to their yard.
You could use an alternative hardwood such a Iroke and stain it to darken it. If you go for lamination, you may have to improvise a steam box to start the bends then tighten the curves within a jig with movable pegs. If you have to joint it, use a router cutter with a deep “v” shape. Good luck.