The next step was a pretty straightforward one, just a simple frame and panel assembly for the back of the case. Since this whole assembly is going to be fastened to the case I just used biscuits to join the frames. I also used biscuits to align and fasten it to the shelf carcass. When it's all said and done I think the case will have plenty of strength despite the shortfalls of biscuits. I also used a few pocket hole screws where they would be hidden.