I would assume most everyone has a drill. We could fab up the boxes and leave it to each person to drill the tabs and flanges on their own. If we keep everything square it may be easier to bend the aluminum. Would two toolboxes be a good design? I'm not sure I would need a water tank.
A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.
It is not the destination, it's the journey.