Well, I know I was considering creating a live edge on the old stair tread, but it didn’t work out. As I got to know the piece of wood, I came to realize it would just look like a badly curved edge, as if I couldn’t cut straight. So I ripped the board to width (5 in.) and sent it through my planer. I was left with a 3 foot long, 7/8 in. thick board with knots in it. So I centered the shelf (15 in) on the knots and used the rest for supports.
The photo shows the pieces unsanded. I put a roman ogee on the underside of the shelf, a small chamfer on the upper edge, and a cove (made by lowering the ogee bit) on the supports.
-- Ni faru ion el ligno!