These inserts we designed to fit in a Bunker Hill Ammo Box you can buy at Harbor Freight. Print 3 of the inside trays and one of the top trays.

These are designed to fit fairly tight in there and the trays do no move around.  This box has a gasket and should be at least water resistant which could make this a good case to take to the beach/lake, whether you are fishing, boating, or just lounging around for the day.