If I were you, id make the brace a bit wider, lag bolt it down. Throw 2x6 across the top to make it one level top rather than having the brace above all. Then sand it down an vanish or stain it. It'll look nice and be stronger =)
Personally id be a little worried about the bottom, looks like you have no wood braces on the bottom either, that's a lot of pressure to not have braces on the bottom.