I think you might be onto something with that idea.
I do not fabricate these boxes, i buy them and fit them to work with the util rails. This keeps the price low. If you look at a across bed tool box they are very big and costly. This box is compact ( 23 gal ) and it would run around $75.I am confused.. you fabricate the boxes?
How do you make them ride on the rail?
The Box itself looks like a regular bin, although the idea is great and I am very interested.
Just help me out to understand the design aspect, mounting and all.