I was thinking powerwedge just for more bling effect (as if it didn't have enough already)
I thought of some other improvements, which I'm sure are overkill-
1) double stack them
2) where Collin suggested welding a plate, do so and add two more LEDs that point straight down
That very last pic that you posted is so picture perfect. It's perfect distribution with no gaps whatsoever. Job well done.