I have to get a better shooting box though. Your's looks just about perfect!
Here are some photos of my shooting box. If they help anyone come up with a good design for themselves, then great...
This is an all-oak box made by Fuzzy Johnson of First Frontier Militia in Bowmanstown, PA. It is approx. 16" wide, 12" deep, and 12" high. It holds everything for a day at the range. I generally do not carry my roundballs in it, as it would get heavy.
The box holds two cans of powder on the right side, as well as cleaning solvent (blue spray bottle), oil, Lehigh Valley Lube, spray lubricant, ramrod tips and accessories in an Altoids can, and some alcohol.
The tray holds a lot of smaller items including shooting glasses, ear plugs, short starters, calipers, tins of patches and flints, and more.
The bottom of the box holds larger items such as a brass machinist hammer, a 4oz. rubber mallet, large scissors, screwdriver with an assortment of bits, rod puller, stapler, large bag of 2" patches for my .62s, extra pillow ticking either rolled or folded (1/2 yard or so; I never want to be without). The only thing I cannot get into the box that I would love to have is my 28oz. Deadforce black rubber mallet that I purchased from Lowe's.
By the way, when I go to primitive events, I don't carry all of this equipment. I am very comfortable loading out of the bag. I do carry a wooden wiping stick/"range" rod though.
If you have any questions, feel free to ask. This is my system that I am comfortable with. It may work for some of you; but then again, it may not.
James