If the grain is running horizontal ( in reference to the pic), than it looks plenty stout enough to hold. If vertical it might break.
7' dowel?? The dowel I mentioned goes into the bracket from the wall outboard, maybe 4" long. Worked real well on mine.I start vacation Wednesday and I'm headed on a 1 1/2 hour, one-way road trip for lumber. Found a guy selling walnut and maple for $2.25 a BF as well as oak for $2.00 a BF.
I like the idea of extending the bracket below the notch to allow for more wood and better support. As for dowels, I'm not sure I even know where to buy a 7' dowel. My thought was to glue 2 pieces of walnut together into approx. 1.5" square by 7' rod. Then router the corners to make it into a hexagonal type shape. I thought it might give more support.
As for scroll work, I have a 16" scroll saw that I haven't used. It was given to me by my father-in-law. This might be a good time to pull it out and give it a try....on scrap wood first!
Thanks for all the replies! Man I love this site!