Ever since I built my EP, I've wanted to cover the exposed plywood edge on the next boat's rub rails. I milled an "L" in the mahogany. It's a 3/16" x 6mm "extension" to the 1/2" x 7/8" rub rail stock. It covers the edge perfectly and looks great on the interior. I will use wood flour instead of silica for the optics.
I'm posting this technique in case someone else finds it useful and also to read any constructive criticizm anyone may have.
Also, in order to make the 1:8 scarf joints on the rub rails, I just set my miter saw to 7.5° and used a 90° jig to keep the long, thin stock square and supported in the miter saw. This produced a 4" long scarf joint for the 1/2" thick rub rail layers.