It's available at my local supplier in a good variety of widths and lengths(one of the renewable mahogany type species). Only 3/4" though(unless I special order) so I plan to glue it up(epoxy) to 1 1/2" thick blanks. I've used quite a bit in repairs, additions, on my boat and it finishes very well bright, takes paint very well, has good weather resistance.

The idea is glued up stock of 6"x 1 1/2" x length of rails. Each piece of stock will yield two rails. @ 8.00/ bd ft., cost about 4.00 / running foot of hand rail that is custom sized for my boat. cheap!

I'm thinking....;

1- a 3" hole saw/drill press on center to define each opening(I've started a CAD file and working on spacing, profile).

2- Rip down the center to yield 2 rough blanks.

3- band saw out between 3" half circles, leaves fastening legs between.

4-bevel on table saw from wider base to finer top(not sure on this, considering what Paul mentioned as well)
plane or sand(not sure how cut out will work on joiner) smooth

5-shape rounds with router to finish from wide bases 1 1/4"? to 360 degree handle top of 1"? Completely finish;paint or varnish, not sure....

Fastening to wood so new holes are no problem. I'm thinking a piece of 2x stock cut to the sweep of my cabin taper, will clamp the new rails to that template. Mark feet, drill from above, replace clamped template/rails, drill, fasten.