To install non-curved feet on a curved deck:

Cut a nice set of wooden pieces from one inch mahogany or teak. Attach the pieces temporarily to the feet (hint: pay attention to the orientation of the grain!) with *short* wood screws that don't go
through the wood.  Twist/tweek/stretch the rail so that all of the wood pieces "sit" where you want them on the deck without any applied pressure.  Mark the footprints on the deck and prep the surface to
receive bonding.  Remove any wood core material where the bolts will penetrate the deck, and fill with epoxy.  "Goop" the bottom of the wood pieces with 5200 or Marine-Tex.  Set the rail in place and
restrain to prevent movement during curing.  Remove excess goop before it dries.  After the bonding cures, remove the wood screws (which should not have penetrated the Marine-Tex!) and drill for
thru-bolting.  Apply your preferred wood finish.  Bolt the rail down, stand back and admire!

I fitted my wood "foot-pads" with a flat side on each to match the molded cap at the Triton's deck-edge.  My one mistake was forgetting to allow for drainage.  Now I have catch-waters aft of the side feet on the stern rail.  If I were doing it again, I think I'd save a few polyethylene straws and use one under each foot to form a drainage tunnel at the outboard edge.  Use a length of appropriately sized
wire through each straw to prevent it from getting crushed during installation.