After some chiseling, the dados for the shelf, case divider and back panel were done. The Mahogany didn’t give me any trouble to day.
So here are the steps:
1. Mark out the lines based on the center line of the shelf/divider and using the piece to size.
2. Chisel out a valley for the saw to fit.
3. Drill out the end so the saw will have an opening.
4. Saw the side walls. I ended up using a block as a guide to get the saw started.
5. Chisel out the waste.
6. Finish up with a router.