VaughnT,
Maybe I shouldn't have made the sewing machine box comparison. That was just for proportions, not similar function.
Also, remember that the box I described is my existing box. The plans could be for something very different.
On my box the front and back are hinged at the bottom and open down. Each panel opens the entire side except for about the bottom three inches, which is where the ammo tray sits, and also takes about a 1 1/2" lip from the top and ends. The ends support two shelves, which hold everything except the ammo, and the top, which is basically a third shelf. The top is still wide enough for the short tripod on my spotting scope to sit on it. The handle is a dowel that extends to both ends so the tripod has to straddle it, but that works out well since it also keeps the tripod from getting far enough off-center to fall off. Actually, the top of my box is a little more complicated than this but it's kind of hard to describe. But the difference is in how it works/looks closed. I never cared for the top-hinged doors. They give you a good spot for a scope but you have to reach around/under them for everything you want to get out of the box.
Being right-handed, I put my box on the bench to my left with the front of the box facing to my right. You can get to everything except the targets by opening the front of my box which drops down on the bench in front of you and becomes your work surface for loading. The angle of the top makes loose shells roll to the right side and the magnetic magazine holder (strip) is on the left, near and parallel to the hinge.
The back of the box is now to the left and stores targets as well as providing access to the other side of the storage areas. This lid has a 1/4" thick plywood panel inside which removes by sliding it away from the hinge about an inch. The targets are in a 1/2" deep compartment between the back and the panel. With the lid open this panel becomes the scoring desk or it can be lifted out and used as a lapboard. (With both lids open the box is too wide if people are trying to shoot along side you.)
My gun rugs are lamb's wool on one side and nylon cordura on the other. They're about 18" square when open and can be folded in half and secured with a velcro strip to protect a gun if so desired.
Hand_Rifle_Guy,
I like the idea of the tripod leveling leg. I may try to work something like that into the new box design. I've kind of stayed away from rubber feet on my boxes. Mainly because most of them don't attach very well and get knocked off pretty easy. My current box has very simple, and easy to duplicate, oak feet to protect the corners. The only nails (brads actually) in the box are holding the feet on. That's so I don't have to damage the box to change the feet if they get damaged.
I've modified a couple of grips slightly but I've never made my own. But that's because I'm kind of fond of Hogue grips and that rubber clogs up my Dremel tool.
Tom