John,I really like yor idea. Wish I had the idea or had read your post before I did mine. (that was about two years ago).
Chuck I just went out to the garage to look at my Great Auk's risers and how I did it. I put a fillet around, but as I rememer, not until I had put the comming on. It was ackward doing it that way. Put it on before and make it small - 1/4 inch or so. Mine is about 3/8 to 1/2 and hides the stripes in the riser. Hope this helps.