Stand Structural Integrity

[rstar]

Hey all! Just wondering what you engineering types think about the structural integrity of my stand! The boxes of the stand are held to each 4X4 by three stainless 2.5" screws and one 4" screw. Should I add a couple 2x4's along the back and side on the inside of the stand connecting the two boxes? I built the stand like this because i wanted the pedastal look. So i would like to keep the outside the way it is.