Decided to go ahead and use the Walnut carving for the fireplace mantle since I had gotten the lights for the deck carving.
Fitting the boards to the cement work on the fireplace proved to be a bit more time consuming than I anticipated.
I started out thinking I could just use a compass to transfer my lines, however that proved to be somewhat difficult since the "rocks" in some places were higher out below the edge of the board, so I used a 4" angle grinder with oriented carbide disk to taper the edges back.
This mantle was quite a bit larger than the existing one. I also needed to incorporate the LED dimmer.
The end board became somewhat time consuming to make for the correct depth to let the slide switch be accessible and to notch for the wires, also the scroll carvings on both sides (by hand).
Kind of sloppy on the backside but it can't be seen anyway.
Finished and installed, I decided I needed to use screws to allow access to the dimmer circuit if the need ever arises.
Since we're limited to 4 pictures per post I'll finish up in a reply.
Thanks ~Mike