It looks really good, hopefully it will stand up to weather and recoil.
The only thing I think you could have done to make it look better is a tighter fit, again not that it looks bad it doesn't.
When I've run into a mating two pieces together situation I did the following:
I made a plywood template of the convex piece, lightly fill the endgrain with bondo and sand smooth, cover the edge with Mylar tape and lightly rub with wax, roughcut a piece to mate to it, doesn't have to be perfect, spread a generous amount of bondo on the new piece and squish the two together, sand the flat sides, remove the tape and you have two perfectly mated templates.
I used this technique to rout a 10-22 rifle stock to accept a rubber mini-14 butt pad. Worked pretty well.
Love the grain.