here is a tip
If you have any companies that make manufactured boxes, they always make extras on an order and will sell them cheap if they didn't need them. I used to get great boxes at the company we had here and they always had different sizes. Unfortunately the closed. : (
I can't remember what the name of the place was that I knew they made boxes, maybe something like shipping containers or something, and just went in once to see what it would cost to place an order, then they told me about the extras.